Cathy A. Birkeland

Patrick H. Shannon

Shagufa R. Hossain

Bradley C. Faris

Justin G. Hamill

Latham & Watkins LLP

330 N. Wabash Avenue, Suite

2800

Chicago, IL 60611

(312) 876-7700

Christian O. Nagler

Wayne E. Williams

Aslam A. Rawoof

Kirkland & Ellis LLP

601 Lexington Avenue

New York, NY 10022

(212) 446-4800

Title of each class of

securities to be registered

Class A Common Stock⁽³⁾⁽⁴⁾

Warrants⁽⁵⁾

Class A Common Stock⁽⁴⁾⁽⁷⁾

Total

All securities being registered will be issued by Vivid Seats Inc., a newly incorporated Delaware corporation (“Vivid Seats PubCo”).

Estimated solely for the purpose of calculating the registration fee and calculated in accordance with Rule 457(f)(1) and Rule 457(c) of the Securities Act of 1933, as amended (the “Securities Act”), based on the average of the high and low prices of the Class A ordinary shares of Horizon Acquisition Corporation, a Cayman Islands exempted company (“Horizon”), to be merged with and into Vivid Seats PubCo upon consummation of the business combination, on The New York Stock Exchange (the “NYSE”) on May 24, 2021 of $9.97 per ordinary share.

The number of shares of Class A common stock of Vivid Seats PubCo, par value $0.0001 per share (the “Vivid Seats Class A common stock”), being registered includes (i) up to 54,398,433 shares of Horizon Class A ordinary shares that were sold pursuant to Horizon’s Registration Statement on Form S-1 (File No. 333-240313) as part of the units in Horizon’s initial public offering (the “public shares”), which will convert into shares of Vivid Seats Class A common stock pursuant to the Merger in connection with the business combination described in the proxy statement/prospectus forming part of this registration statement and (ii) 50,000 shares of Vivid Seats Class A common stock to be issued to Horizon Sponsor, LLC, a Delaware limited liability company (“Sponsor”) in connection with the Exchange (as defined below).

Pursuant to Rule 416(a), there are also being registered an indeterminable number of additional securities as may be issued to prevent dilution resulting from share splits, share dividends or similar transactions.

The number of warrants being registered includes 18,132,810 warrants to acquire Horizon Class A ordinary shares that were sold as part of the units in Horizon’s initial public offering. All such Horizon warrants will convert into 18,132,810 warrants to acquire shares of Vivid Seats Class A common stock (the “Vivid Seats Public IPO Warrants”) pursuant to the Merger in connection with the business combination described in the proxy statement/prospectus forming part of this registration statement.

Estimated solely for the purpose of calculating the registration fee and calculated in accordance with Rule 457(f)(1) and Rule 457(c) of the Securities Act, based on the average of the high and low prices of the Horizon IPO Public Warrants on the NYSE on May 20, 2021 of $1.67 per warrant.

Reflects the shares of Vivid Seats Class A common stock that may be issued upon exercise of the warrants.

Calculated pursuant to Rule 457(g) under the Securities Act, based on the exercise price of the warrants.

(a) approve and adopt the Transaction Agreement, dated as of April 21, 2021 (as the same may be amended, the “Transaction Agreement”), by and among Horizon, Sponsor, Hoya Topco, Hoya Intermediate and Vivid Seats PubCo, and (b) approve the other transactions contemplated by the Transaction Agreement (the “business combination” and such proposal, the “Business Combination Proposal”) in accordance with applicable law and exchange rules and regulations;

approve, as a special resolution, the Plan of Merger annexed to the Transaction Agreement and attached to this proxy statement/prospectus as Annex K and to authorize the merger (the “Merger”) of Horizon with and into Vivid Seats PubCo, upon which the separate corporate existence of Horizon will cease and Vivid Seats PubCo will become the surviving corporation (the “Merger Proposal”);

approve certain material differences between the Horizon amended and restated memorandum and articles of association and the certificate of incorporation of Vivid Seats PubCo and the bylaws of Vivid Seats PubCo that will be the certificate of incorporation and bylaws of Vivid Seats PubCo following the Merger (the “Organizational Documents Proposals”);

approve, for purposes of complying with NYSE Listing Rule 312.03, the issuance of shares of Vivid Seats PubCo in connection with the business combination and the PIPE Subscription (the “NYSE Proposal”); and

approve the adjournment of the extraordinary general meeting to a later date or dates, if necessary or appropriate, to permit further solicitation and vote of proxies in the event that there are insufficient votes for, or otherwise in connection with, the approval of the Business Combination Proposal, the Merger Proposal, the Organizational Documents Proposals and the NYSE Proposal (the “Adjournment Proposal” and, together with the Business Combination Proposal, the Merger Proposal, the Organizational Documents Proposals and the NYSE Proposal, the “Proposals”).

Todd L. Boehly

Chief Executive Officer, Chief

Financial Officer and Director

Horizon Acquisition Corporation

Proposal No. 1 — The Business Combination Proposal — To consider and vote upon a proposal to (a) approve and adopt the Transaction Agreement, dated as of April 21, 2021 (as the same may be amended, the “Transaction Agreement”), by and among Horizon, Sponsor, Hoya Topco, Hoya Intermediate and Vivid Seats PubCo, and (b) approve and the other transactions contemplated by the Transaction Agreement (the “business combination” and such proposal, the “Business Combination Proposal”).

Proposal No. 2 — The Merger Proposal — To consider and vote upon a proposal (the “Merger Proposal”) to approve, as a special resolution, the Plan of Merger annexed to the Transaction Agreement and attached to this proxy statement/prospectus as Annex K and to authorize the merger (the “Merger”) of Horizon with and into Vivid Seats PubCo, upon which the separate corporate existence of Horizon will cease and Vivid Seats PubCo will become the surviving corporation.

The Organizational Documents Proposals — To consider and vote upon the following three separate proposals (collectively, the “Organizational Documents Proposals”) to approve the following material differences between Horizon amended and restated memorandum and articles of association and the certificate of incorporation of Vivid Seats PubCo (the “Vivid Seats PubCo Amended and Restated Charter”) and the bylaws of Vivid Seats PubCo (the “Vivid Seats PubCo Amended and Restated Bylaws”) that will be the certificate of incorporation and bylaws of Vivid Seats PubCo following the Merger:

Proposal No. 3 — Organizational Documents Proposal A — To authorize the change in the authorized capital stock of Horizon from 400,000,000 Horizon Class A ordinary shares, par value $0.0001 per share (the “Horizon Class A ordinary shares”), 40,000,000 shares of Horizon Class B ordinary shares, par value $0.0001 per share (the “Horizon Class B ordinary shares”), and 1,000,000 preference shares, par value $0.0001 per share, to 500,000,000 shares of Class A common stock, par value $0.0001 per share, of Vivid Seats PubCo (the “Vivid Seats Class A common stock”), 250,000,000 shares of Class B common stock, par value $0.0001 per share, of Vivid Seats PubCo (the “Vivid Seats Class B common stock”) and 50,000,000 shares of preferred stock, par value $0.0001 per share, of Vivid Seats PubCo.

Proposal No. 4 — Organizational Documents Proposal B — To authorize that certain provisions of the Vivid Seats PubCo Amended and Restated Charter and certain provisions of the Vivid Seats PubCo Amended and Restated Bylaws, in each case, will be subject to the Stockholders’ Agreement (as defined herein).

Proposal No. 5 — Organizational Documents Proposal C — To authorize all other changes in connection with the replacement of Horizon’s amended and restated memorandum and articles of association with the Vivid Seats PubCo Amended and Restated Charter and the Vivid Seats PubCo Amended and Restated Bylaws as part of the Merger (copies of which are attached to this proxy statement/prospectus as Annex C and Annex D, respectively), including (a) changing the corporate name from “Horizon Acquisition Corporation” to “Vivid Seats Inc.,” (b) granting an

Proposal No. 6 — The NYSE Proposal — To consider and vote upon a proposal to approve, for purposes of complying with NYSE Listing Rule 312.03, the issuance of shares of Vivid Seats PubCo in connection with the business combination and the PIPE Subscription (the “NYSE Proposal”).

Proposal No. 7 — The Adjournment Proposal — To consider and vote upon a proposal to approve the adjournment of the extraordinary general meeting to a later date or dates, if necessary or appropriate, to permit further solicitation and vote of proxies in the event that there are insufficient votes for, or otherwise in connection with, the approval of the Business Combination Proposal, the Merger Proposal, the Organizational Documents Proposals and the NYSE Proposal (the “Adjournment Proposal” and, together with the Business Combination Proposal, the Merger Proposal, the Organizational Documents Proposals and the NYSE Proposal, the “Proposals”).

Todd L. Boehly

Chief Executive Officer, Chief Financial Officer

and Director

Horizon Acquisition Corporation

ADDITIONAL INFORMATION

TRADEMARKS

MARKET, INDUSTRY AND OTHER DATA

CERTAIN DEFINED TERMS

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

SUMMARY TERM SHEET

QUESTIONS AND ANSWERS ABOUT THE PROPOSALS FOR HORIZON SHAREHOLDERS

SUMMARY OF THE PROXY STATEMENT/PROSPECTUS

SELECTED HISTORICAL AND PRO FORMA FINANCIAL INFORMATION OF HORIZON

SELECTED HISTORICAL AND PRO FORMA FINANCIAL INFORMATION OF VIVID SEATS

MARKET PRICE, TICKER SYMBOL AND DIVIDEND INFORMATION

RISK FACTORS

EXTRAORDINARY GENERAL MEETING OF HORIZON SHAREHOLDERS

PROPOSAL NO. 1 — THE BUSINESS COMBINATION PROPOSAL

PROPOSAL NO. 2 — MERGER PROPOSAL

ORGANIZATIONAL DOCUMENTS PROPOSALS

PROPOSAL NO. 3 — ORGANIZATIONAL DOCUMENTS PROPOSAL A — APPROVAL OF CHANGE TO AUTHORIZED CAPITAL STOCK, AS SET FORTH IN THE PROPOSED ORGANIZATIONAL DOCUMENTS

PROPOSAL NO. 4 — ORGANIZATIONAL DOCUMENTS PROPOSAL B — APPROVAL OF PROPOSAL REGARDING CERTAIN PROVISIONS OF THE VIVID SEATS PUBCO ORGANIZATIONAL DOCUMENTS BEING SUBJECT TO THE STOCKHOLDERS’ AGREEMENT

PROPOSAL NO. 5 — ORGANIZATIONAL DOCUMENTS PROPOSAL C — APPROVAL OF OTHER CHANGES IN CONNECTION WITH THE VIVID SEATS PUBCO ORGANIZATIONAL DOCUMENTS

PROPOSAL NO. 6 — THE NYSE PROPOSAL

PROPOSAL NO. 7 — THE ADJOURNMENT PROPOSAL

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

OTHER INFORMATION RELATED TO HORIZON

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS OF HORIZON

BUSINESS OF VIVID SEATS

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS OF VIVID SEATS

DESCRIPTION OF CERTAIN INDEBTEDNESS

DESCRIPTION OF VIVID SEATS PUBCO SECURITIES

SECURITIES ACT RESTRICTIONS ON RESALE OF COMMON STOCK

BENEFICIAL OWNERSHIP OF SECURITIES

OFFICERS AND DIRECTORS OF VIVID SEATS PUBCO UPON CONSUMMATION OF THE BUSINESS COMBINATION

EXECUTIVE COMPENSATION

CERTAIN RELATIONSHIPS AND RELATED PERSON TRANSACTIONS

COMPARISON OF CORPORATE GOVERNANCE AND STOCKHOLDERS’ RIGHTS

NO APPRAISAL RIGHTS

STOCKHOLDER PROPOSALS AND NOMINATIONS

SHAREHOLDER COMMUNICATIONS

HOUSEHOLDING INFORMATION

LEGAL MATTERS

EXPERTS

WHERE YOU CAN FIND ADDITIONAL INFORMATION

INDEX TO FINANCIAL STATEMENTS

ANNEX A: TRANSACTION AGREEMENT

ANNEX B: CURRENT CERTIFICATE OF INCORPORATION OF VIVID SEATS PUBCO

ANNEX C: FORM OF PROPOSED AMENDED AND RESTATED CERTIFICATE OF INCORPORATION OF VIVID SEATS PUBCO

ANNEX D: FORM OF AMENDED AND RESTATED BYLAWS OF VIVID SEATS PUBCO

ANNEX E: FORM OF STOCKHOLDERS’ AGREEMENT

ANNEX F: FORM OF TAX RECEIVABLE AGREEMENT

ANNEX G: FORM OF 2021 INCENTIVE AWARD PLAN

ANNEX H: FORM OF 2021 EMPLOYEE STOCK PURCHASE PLAN

ANNEX I: FORM OF SUBSCRIPTION AGREEMENT

ANNEX J: FORM OF SECOND AMENDED AND RESTATED LIMITED LIABILITY COMPANY AGREEMENT OF HOYA INTERMEDIATE

ANNEX K: FORM OF PLAN OF MERGER

ANNEX L: FORM OF AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT

PART II: INFORMATION NOT REQUIRED IN PROSPECTUS

“2021 ESPP” are to the Vivid Seats Inc. 2021 Employee Stock Purchase Plan;

“2021 Plan” are to the Vivid Seats Inc. 2021 Incentive Award Plan;

“Agreement End Date” are to October 21, 2021;

“Available Horizon Cash” are to the cash available in the Trust Account;

“Blocker Corporations” are to the Blocker Corporations as defined in the Tax Receivable Agreement;

“business combination” are to the transactions contemplated by the Transaction Agreement, including, (a) the Merger, (b) the Class A Redemption, (c) the Blocker Purchase, (d) the Crescent Redemption, (e) the Intermediate Contribution and Issuance and (f) the Class B Issuance;

“CICA” is to the Companies Act (As Revised) of the Cayman Islands;

“Class A Redemption” are to the redemption by Hoya Topco of 100% of the outstanding Class A Units of Hoya Topco held by the Redeemed Crescent Parties in exchange for Common Units of Hoya Intermediate;

“Class B Issuance” are to the issuance at the Closing by Vivid Seats PubCo to Hoya Topco of 118,200,000 shares of Vivid Seats Class B common stock and warrants to purchase 6,000,000 shares of Vivid Seats Class B common stock at the Closing;

“Closing” are to the consummation of the business combination;

“Closing Date” are to the date the Closing takes place;

“Code” are to the U.S. Internal Revenue Code of 1986, as amended;

“Crescent Holders” are to the Crescent Blockers and the Redeemed Crescent Parties;

“DGCL” are to the General Corporation Law of the State of Delaware;

“Effective Time” are to the time at which the Merger becomes effective pursuant to the Transaction Agreement;

“Existing Warrant Agreement” are to that certain Warrant Agreement, dated as of August 20, 2020, between Continental Stock Transfer & Trust Company and Horizon;

“Form of New Warrant Agreement” are to that certain warrant agreement to be entered into by and among Vivid Seats PubCo and Continental Stock Transfer & Trust Company;

“founder shares” are to Horizon Class B ordinary shares initially purchased by Sponsor in a private placement prior to the IPO, and the Horizon Class A ordinary shares issued upon the conversion thereof;

“Horizon $10.00 Exercise Warrants” are to warrants for Horizon Class A ordinary shares with an exercise price of $10.00, to be issued in connection with the Exchange;

“Horizon $15.00 Exercise Warrants” are to warrants for Horizon Class A ordinary shares with an exercise price of $15.00, to be issued in connection with the Exchange;

“Horizon Class A ordinary shares” are to Horizon’s Class A ordinary shares, par value $0.0001 per share;

“Horizon Class B ordinary shares” are to Horizon’s Class B ordinary shares, par value $0.0001 per share;

“Horizon Equityholders” are to Horizon and any investment vehicles or funds managed or controlled, directly or indirectly, by any of Horizon’s affiliates;

“Horizon IPO Private Placement Warrants” are to the warrants sold by Horizon as part of the private placement in connection with the IPO;

“Horizon IPO Public Warrants” are to the warrants sold by Horizon as part of the units in the IPO;

“Horizon ordinary shares” are to Horizon Class A ordinary shares and Horizon Class B ordinary shares, collectively;

“Horizon Share Redemption” are to the election of an eligible (as determined in accordance with Horizon’s governing documents) holder of shares of Horizon ordinary shares to redeem all or a portion of the shares of Horizon ordinary shares held by such holder at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest (which interest shall be net of taxes payable and up to $100,000 of interest to pay dissolution expenses), divided by the number of then issued and outstanding Horizon ordinary shares, which redemption will completely extinguish public shareholders’ rights as shareholders of Horizon (including the right to receive further liquidation distributions, if any), in connection with the Proposals;

“Horizon Share Redemption Amount” are to the aggregate amount payable with respect to all Horizon Share Redemptions;

“Horizon Shareholder Approval” are to the approval of the Proposals, in the case of the Business Combination Proposal, the Organizational Documents Proposals, the NYSE Proposal and the Adjournment Proposal, by an affirmative vote of the holders of at least a majority of the outstanding shares of Horizon ordinary shares entitled to vote and actually cast thereon (as determined in accordance with Horizon’s governing documents) at a Horizon Shareholders’ Meeting duly called by Horizon’s board of directors and held for such purpose or, in the case of the Merger Proposal, by an affirmative vote of the holders of a majority of at least two-thirds of the outstanding shares of Horizon ordinary shares entitled to vote and actually cast thereon (as determined in accordance with Horizon’s governing documents) at a Horizon Shareholders’ Meeting duly called by Horizon’s board of directors and held for such purpose;

“Horizon Shareholders’ Meeting” are to a meeting of Horizon’s shareholders convened and held in accordance with Horizon’s governing documents and Section 710 of the NYSE Listing Rules;

“Horizon Warrants” are to the Horizon IPO Public Warrants, Horizon IPO Private Placement Warrants, the Horizon $10.00 Exercise Warrants and the Horizon $15.00 Exercise Warrants;

“Hoya Intermediate Warrants” are warrants issued by Hoya Intermediate to Vivid Seats PubCo and Hoya Topco;

“Intermediate Common Units” means Common Units of Hoya Intermediate;

“Intermediate Contribution and Issuance” means the contribution by Vivid Seats PubCo of cash to Hoya Intermediate in exchange for Intermediate Common Units and warrants to purchase Intermediate Common Units;

“Intermediate Merger” are to the merger of a newly formed subsidiary of Hoya Topco with and into Hoya Intermediate, pursuant to which, among other things, Hoya Intermediate will recapitalize its existing common units, preferred units and senior preferred units;

“IPO” are to Horizon’s initial public offering of units, the base offering of which closed on August 25, 2020;

“Lock-up Period” are to the period beginning on the Closing Date and ending on the date that is twelve (12) months following the Closing Date;

“lock-up shares” are to (a) with respect to Sponsor, the shares of Vivid Seats PubCo common stock and warrants exercisable for shares of Vivid Seats PubCo common stock held by Sponsor and its affiliates (other than any such shares acquired in connection with the PIPE Subscription) and (b) with respect to Hoya Topco, any Vivid Seats PubCo common stock and any warrants exercisable for shares of Vivid Seats PubCo common stock held by Hoya Topco and its affiliates;

“Marketplace GOV” are to the total transactional amount of Marketplace segment orders placed on the Vivid Seats platform in a period, inclusive of fees, exclusive of taxes, and net of event cancellations that occurred during that period;

“Merger” are to the merging of Horizon with and into Vivid Seats PubCo, upon which the separate corporate existence of Horizon will cease and Vivid Seats PubCo will be the surviving entity;

“Minimum Available Horizon Cash Amount” is $380.0 million;

“NAV” are to net asset value;

“PIPE Investors” are to the qualified institutional buyers and accredited investors, including Sponsor or its affiliates, that have agreed to purchase shares of Vivid Seats Class A common stock in the PIPE Subscription;

“PIPE Subscription” are to the issuance and sale of shares of Vivid Seats Class A common stock to the PIPE Investors in a private placement that will close concurrently with the Closing;

“Private Equity Owner” are to, collectively, GTCR Fund XI/B LP, GTCR Fund XI/C LP, GTCR Co-Invest XI LP, GTCR Golder Rauner, L.L.C., GTCR Golder Rauner II, L.L.C., GTCR Management XI LLC and GTCR LLC;

“private placement units” are to the units of Horizon issued to Sponsor in a private placement simultaneously with the closing of the IPO;

“public shareholders” are to the holders of Horizon’s public shares;

“public shares” are to Horizon Class A ordinary shares sold as part of the units in the IPO (whether they were purchased in the IPO or thereafter in the open market);

“Registration Rights Agreement” are to that certain Amended and Restated Registration Rights Agreement to be entered into by and among Vivid Seats PubCo, Sponsor, Hoya Topco and the other holders party thereto;

“Reorganization Transaction” are to a Reorganization Transaction as defined in the Tax Receivable Agreement;

“Sponsor” are to Horizon Sponsor, LLC, a Delaware limited liability company;

“Sponsor Agreement” are to that certain Sponsor Agreement, dated as of April 21, 2021, by and among Eldridge Industries, LLC, Sponsor, Horizon and Hoya Topco;

“Stockholders’ Agreement” are to that certain Stockholders’ Agreement to be entered into by and among Vivid Seats PubCo, Sponsor and Hoya Topco;

“Tax Receivable Agreement” are to that certain Tax Receivable Agreement to be entered into by and among Vivid Seats PubCo, Hoya Intermediate, the TRA Holder Representative, Hoya Topco and the other TRA Holders;

“Topco Equityholders” are to (a) Hoya Topco or (b) after the distribution (in the aggregate pursuant to one or more distributions) by Hoya Topco of more than 50% of the voting shares of Vivid Seats PubCo held by Hoya Topco on the Closing Date, (i) GTCR Fund XI/B LP, GTCR Fund XI/C LP, GTCR Co-Invest XI LP, GTCR Golder Rauner, L.L.C., GTCR Golder Rauner II, L.L.C., GTCR Management XI LLC and/or GTCR LLC and (ii) any investment vehicles or funds managed or controlled, directly or indirectly, by or otherwise affiliated with the foregoing entities;

“Total Marketplace orders” are to the volume of Marketplace segment orders placed on the Vivid Seats platform during a period, net of event cancellations occurring during the period;

“Total Resale orders” are to the volume of Resale segment orders sold by the Vivid Seats’ resale team in a period, net of event cancellations that occurred during that period;

“TRA Holder Representative” are to GTCR Management XI, LLC;

“TRA Holders” are to the TRA Holders as defined in the Tax Receivable Agreement;

“Transactions” means the PIPE Subscription and the business combination;

“Transaction Agreement” are to the Transaction Agreement, dated as of April 21, 2021, by and among Horizon, Sponsor, Hoya Topco, Hoya Intermediate and Vivid Seats PubCo;

“Trust Account” are to the trust account for the benefit of Horizon, certain of its public shareholders and the underwriter of the IPO;

“Trust Agreement” are to that certain Investment Management Trust Agreement, dated as of August 25, 2020, between Horizon and Continental Stock Transfer & Trust Company, as trustee;

“Trust Amount” are to the amount of cash available in the Trust Account as of the Closing, after deducting the amount required to satisfy Horizon’s obligations to its shareholders (if any) that exercise their redemption rights;

“units” are to Horizon’s units sold in the IPO, each of which consists of one Horizon Class A ordinary share and one third of one Horizon Public IPO Warrant;

“Vivid Seats” are to, prior to the consummation of the business combination, Hoya Intermediate and its consolidated subsidiaries and, following the consummation of the business combination, to Vivid Seats PubCo and its consolidated subsidiaries;

“Vivid Seats Class A common stock” are to Vivid Seats PubCo’s Class A common stock, par value $0.0001 per share;

“Vivid Seats Class B common stock” are to Vivid Seats PubCo’s Class B common stock, par value $0.0001;

“Vivid Seats Companies” are to Hoya Intermediate and its subsidiaries;

“Vivid Seats PubCo” are to Vivid Seats Inc., a Delaware corporation;

“Vivid Seats PubCo $10.00 Exercise Warrants” are to warrants for Vivid Seats Class A common stock with an exercise price of $10.00, to be issued in exchange for the Horizon $10.00 Exercise Warrants, with terms consistent with the Form of New Warrant Agreement to be entered into in connection with the business combination;

“Vivid Seats PubCo $15.00 Exercise Warrants” are to warrants for Vivid Seats Class A common stock with an exercise price of $10.00, to be issued in exchange for the Horizon $15.00 Exercise Warrants, with terms consistent with the Form of New Warrant Agreement to be entered into in connection with the business combination;

“Vivid Seats PubCo Amended and Restated Bylaws” are to the amended and restated bylaws of Vivid Seats PubCo that will be in effect immediately prior to the Effective Time;

“Vivid Seats PubCo Amended and Restated Charter” are to the amended and restated certificate of incorporation of Vivid Seats PubCo that will be in effect immediately prior to the Effective Time;

“Vivid Seats PubCo Class B Warrants” are to warrants for Vivid Seats Class B common stock, to be exercisable upon the exercise of Hoya Intermediate Warrants held by Hoya TopCo;

“Vivid Seats PubCo common stock” are to the Vivid Seats Class A common stock and the Vivid Seats Class B common stock, collectively;

“Vivid Seats PubCo Warrants” are to the warrants for Vivid Seats Class A common stock and Vivid Seats Class B common stock;

“Vivid Seats Private Placement IPO Warrants” are to warrants for Vivid Seats Class A Common Stock, with terms identical to the Horizon IPO Private Placement Warrants; and

“Vivid Seats Public IPO Warrants” are to warrants for Vivid Seats Class A common stock, with terms identical to Horizon IPO Public Warrants.

Horizon’s or Vivid Seats’ ability to consummate the business combination or, if Horizon does not complete the business combination, any other initial business combination;

the benefits of the business combination;

any other satisfaction or waiver (if applicable) of the conditions to the business combination, including, among other things: the satisfaction or waiver of certain customary closing conditions, including, among others, the existence of no material adverse effect at Horizon or Vivid Seats and receipt of certain stockholder approvals contemplated by this proxy statement/prospectus;

the occurrence of any other event, change or other circumstances that could give rise to the termination of the Transaction Agreement;

the ability to obtain the listing of Vivid Seats PubCo’s Class A common stock and warrants on Nasdaq following the business combination;

Horizon’s and Vivid Seats PubCo’s public securities’ potential liquidity and trading;

the ability of Horizon and Vivid Seats to consummate the PIPE Subscription or raise financing in the future;

members of Horizon’s management team allocating their time to other businesses and potentially having conflicts of interest with Horizon’s business or in approving the business combination;

the use of proceeds not held in the Trust Account or available to Horizon from interest income on the Trust Account balance;

the future financial performance of Vivid Seats following the business combination;

Vivid Seats’ success in retaining or recruiting, or changes required in, its officers, key employees or directors following the business combination;

Vivid Seats’ ability to pay dividends on the Vivid Seats Class A common stock following the business combination, on the terms currently contemplated or at all;

factors relating to the business, operations and financial performance of Vivid Seats, including, but not limited to:

the impact of the COVID-19 pandemic on Vivid Seats’ business and the industries in which it operates;

the ability of Vivid Seats to compete in the ticketing industry;

the ability of Vivid Seats to maintain relationships with buyers, sellers and distribution partners;

the ability of Vivid Seats to continue to improve its platform and maintain and enhance its brand;

the impact of extraordinary events or adverse economic conditions on discretionary consumer and corporate spending or on the supply and demand of live events;

the ability of Vivid Seats to comply with domestic regulatory regimes;

the ability of Vivid Seats to successfully defend against litigation;

the ability of Vivid Seats to maintain the integrity of its information systems and infrastructure, and to mitigate possible cyber security risks;

the ability of Vivid Seats to generate sufficient cash flows or raise additional capital necessary to fund its operations; and

other factors detailed under the section entitled “Risk Factors.”

Horizon Acquisition Corporation, a Cayman Islands exempted company (“Horizon”), is a blank check company formed for the purpose of effecting a merger, capital stock exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses (an “initial business combination”).

There are currently (a) 54,398,433 Horizon Class A ordinary shares issued and outstanding, of which 15,500,000 Horizon Class A ordinary shares are held by the Sponsor, (b) 13,599,608 Horizon Class B ordinary shares issued and outstanding, all of which are held by Sponsor and (c) 1,000,000 preference shares of par value $0.0001 each, of which no shares are issued and outstanding. In addition, there are currently 24,652,580 warrants of Horizon outstanding, consisting of 18,132,811 Horizon IPO Public Warrants originally issued in the IPO, of which 5,166,666 Horizon IPO Public Warrants are held by Sponsor, and 6,519,791 Horizon IPO Private Placement Warrants issued to Sponsor concurrently with the IPO in the private placement. Each whole warrant entitles the holder to purchase one whole share of Horizon Class A ordinary shares for $11.50 per share. The warrants will become exercisable on the later of the date that is (i) thirty (30) days after the Closing and (ii) twelve (12) months after the closing of the IPO. Additionally, the warrants will expire five years after the Closing or earlier upon redemption or liquidation. The Horizon IPO Public Warrants and Horizon IPO Private Placement Warrants will be exchanged for the Vivid Seats Public IPO Warrants and Vivid Seats Private Placement IPO Warrants with substantially similar terms upon consummation of the Transactions. Once the Vivid Seats Public IPO Warrants and Vivid Seats Private Placement IPO Warrants become exercisable, Vivid Seats PubCo may redeem them, in whole and not in part, (A) for cash at a price of $0.01 per warrant, if the last reported sale price of Vivid Seats Class A common stock for any twenty (20) trading days equals or exceeds $18.00 per share within a thirty (30) trading-day period ending on the third trading day prior to the date on which Vivid Seats PubCo sends the notice of redemption to the warrant holders or (B) for Vivid Seats Class A common stock at a price of $0.10 per warrant, if the last reported sale price of Vivid Seats Class A common stock for any twenty (20) trading days equals or exceeds $18.00 per share within a thirty (30) trading-day period ending on the third trading day prior to the date on which Vivid Seats PubCo sends the notice of redemption to the warrant holders.

Pursuant to the Exchange Agreement, dated as of April 21, 2021, by and between Horizon and Sponsor (the “Exchange Agreement”), and effective at least one day prior to the Merger, Sponsor will irrevocably tender to Horizon all of its Horizon Class B ordinary shares for cancellation in exchange for (i) warrants to purchase 17,000,000 shares of Horizon Class A ordinary shares at an exercise price of $10.00 per share (the “Horizon $10.00 Exercise Warrants”), (ii) warrants to purchase 17,000,000 shares of Horizon Class A ordinary shares at an exercise of $15.00 per share (the “Horizon $15.00 Exercise Warrants”) and (iii) 50,000 shares of Horizon Class A ordinary shares, as more particularly set forth therein (collectively, the “Exchange”). The Horizon $10.00 Exercise Warrants and the Horizon $15.00 Exercise Warrants shall be issued to Sponsor on terms set forth in the Form of New Warrant Agreement, including that, the Horizon $10.00 Exercise Warrants and the Horizon $15.00 Exercise Warrants (i) will have an exercise price of $10.00 per share and $15.00 per share, respectively, (ii) will each have a term of ten (10) years, (iii) will not be redeemable by Horizon or, upon conversion to Vivid Seats PubCo Warrants, Vivid Seats PubCo, and (iv) will be fully transferrable, except for any contractual restrictions on transfer set forth in the Stockholders’ Agreement and the Sponsor Agreement. For more information about Horizon, see the sections entitled “Other Information Related to Horizon” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations of Horizon.”

Vivid Seats is a leading full-service ticketing marketplace enabling fans and event seekers to purchase tickets to sports, concerts, theater and other live events. For more information regarding Vivid Seats, see the section entitled “Business of Vivid Seats.”

On April 21, 2021, Horizon entered into the Transaction Agreement, pursuant to which: (a) at least one day prior to the Merger, Sponsor and Horizon will effect the Exchange, (b) prior to the Merger, Hoya Topco and Vivid Seats will effect the Pre-Closing Restructuring (as defined in the Transaction Agreement), which will include (i) the redemption by Hoya Topco of 100% of the outstanding Class A Units of Hoya Topco (the “Class A Redemption”) held by the Crescent Holders in exchange for common units of Hoya Intermediate and (ii) the formation of a new subsidiary of Hoya Topco, which will merge with and into Hoya Intermediate (the “Intermediate Merger”), pursuant to which, among other things, Hoya Intermediate will recapitalize its existing common units, preferred units and senior preferred units such that each existing common unit will be converted into a certain number of new Intermediate Common Units (and, in the case of common units held by Hoya Topco, 118,200,000 Intermediate Common Units and Hoya Intermediate Warrants consisting of (i) warrants to purchase 3,000,000 Intermediate Common Units at an exercise price of $10.00 per share and (ii) warrants to purchase 3,000,000 Intermediate Common Units at an exercise price of $15.00 per share), each existing preferred unit will be converted into a Class I Unit of Hoya Topco and each existing senior preferred unit will be cancelled and cease to exist, (c) Horizon will merge with and into Vivid Seats PubCo, upon which the separate corporate existence of Horizon will cease and Vivid Seats PubCo will become the surviving entity in the Merger, (d) the Amended and Restated Limited Liability Agreement of Hoya Intermediate, dated as of June 30, 2017, as amended, will be amended and restated in the form attached to this proxy statement/prospectus as Annex J (the “Second A&R LLCA”), (e) Vivid Seats PubCo will purchase the Crescent Blockers in the Blocker Purchase, (f) Vivid Seats PubCo and Hoya Intermediate will consummate the Intermediate Contribution and Issuance, (g) Hoya Intermediate will redeem the Intermediate Common Units held by the Redeemed Crescent Parties in the Crescent Redemption, (h) Vivid Seats PubCo will issue Vivid Seats Class B common stock and warrants to purchase Vivid Seats Class B common stock to Hoya Topco in the Class B Issuance and (i) Hoya Intermediate will contribute a portion of the funds received from Vivid Seats PubCo to Hoya Midco for repayment of a portion of its existing debt obligations.

In connection with the execution of the Transaction Agreement, Horizon entered into the following agreements:

PIPE Subscription Agreements.    Horizon and Vivid Seats PubCo entered into the subscription agreements (the “Subscription Agreements”) with the PIPE Investors, pursuant to which the PIPE Investors have agreed to subscribe for and purchase, an aggregate of 22,500,000 shares of Vivid Seats Class A common stock, in a private placement for a purchase price of $10.00 per share, for aggregate gross proceeds of $225.0 million; provided, however, such subscription is subject to increase due to Sponsor Backstop Commitment (as defined below). Eldridge Industries, LLC, an affiliate of Sponsor, has agreed to purchase 19,000,000 shares of Vivid Seats Class A Common Stock in a private placement for a purchase price of $10.00 per share in the PIPE Subscription. The Subscription Agreements provide that Vivid Seats PubCo will grant the investors in the PIPE Subscription certain customary registration rights. Vivid Seats PubCo will, within 30 days after the consummation of the business combination, file with the Securities and Exchange Commission (the “SEC”) a registration statement registering the resale of such shares of Vivid Seats Class A Common Stock and will use its commercially reasonable efforts to have such registration statement declared effective as soon as practicable after the filing thereof. The closing of the PIPE Subscription is contingent upon, among other things, the substantially concurrent consummation of the business combination. For more information about the Subscription Agreements, see the section entitled “Proposal No. 1 — The Business Combination Proposal — Related Agreements — PIPE Subscription Agreements.”

Sponsor Agreement.    Horizon entered into a sponsor agreement with Eldridge Industries, LLC, Sponsor and Hoya Topco (the “Sponsor Agreement”), pursuant to which Sponsor agreed to vote in favor of the Proposals, in each case, subject to the terms and conditions contemplated by the Sponsor Agreement. Sponsor also agreed to (a) waive certain anti-dilution protections it may be entitled to under Horizon’s organizational documents or otherwise, (b) certain transfer restrictions on the Horizon ordinary shares and Horizon Warrants beneficially owned by Sponsor and its affiliates, (c) not to solicit any business combination other than the business combination with Hoya Topco, in each case, subject to limited exceptions as contemplated thereby and (d) increase the amount of its subscription of shares of Vivid Seats Class A common stock by the amount the available cash held by Vivid Seats PubCo at the closing of the business combination is less than approximately $769 million (the “Sponsor Backstop Commitment”), in consideration for a fee of approximately $11.7 million. For more information about the Sponsor Agreement, see the section entitled “Proposal No. 1 — The Business Combination Proposal — Related Agreements — Sponsor Agreement.”

In connection with the Closing, Vivid Seats PubCo will enter into, among others, the following agreements:

Vivid Seats PubCo Amended and Restated Charter.    Pursuant to the terms of the Transaction Agreement, the Vivid Seats PubCo Amended and Restated Charter will be the certificate of incorporation of Vivid Seats PubCo following the Closing, which will, among other things, provide for three classes of stock, the Vivid Seats Class A common stock, which will be issued to Sponsor, the PIPE Investors and the other public shareholders of Vivid Seats PubCo in connection with the Closing, the Vivid Seats Class B common stock, which will be issued to Hoya Topco in connection with the Class B Issuance and preferred stock, none of which will be outstanding immediately following the Closing. For more information about the Vivid Seats PubCo Amended and Restated Charter, see section entitled “Proposal No. 1 — The Business Combination Proposal — Related Agreements — Vivid Seats PubCo Amended and Restated Charter.”

Second A&R LLCA.     At the Closing, Hoya Intermediate, Vivid Seats PubCo and Hoya Topco will enter into the Second A&R LLCA, which will set forth, among other things, the rights and obligations of the members and board of managers of Hoya Intermediate. For more information about the Second A&R LLCA, see the section entitled “Proposal No. 1 — The Business Combination Proposal — Related Agreements — Second A&R LLCA.”

Registration Rights Agreement.    At the Closing, Vivid Seats PubCo, Sponsor and Hoya Topco will amend and restate the Registration and Shareholder Rights Agreement, dated as of August 25, 2020, by and between Horizon and the Sponsor. Pursuant to the Registration Rights Agreement, Vivid Seats PubCo will agree to file a registration statement for a shelf registration on Form S-1 or Form S-3 within 30 days following Closing and Sponsor and Hoya Topco will be granted certain customary registration rights with respect to the securities of Vivid Seats PubCo. For more information about the Registration Rights Agreement, see the section entitled “Proposal No. 1 — The Business Combination Proposal — Related Agreements — Registration Rights Agreement.”

Stockholders’ Agreement.    The Transaction Agreement contemplates that, at the Closing, Vivid Seats PubCo will enter into a Stockholders’ Agreement with Sponsor and Hoya Topco, pursuant to which, among other things, the board of directors of Vivid Seats PubCo (the “Vivid Seats Board”) will consist of nine (9) directors, comprised of (i) the chief executive officer of Vivid Seats PubCo, (ii) five (5) directors designated by the Topco Equityholders (as defined herein) and (iii) three (3) directors designated by the Horizon Equityholders (as defined herein). Additionally, the Stockholders’ Agreement contains certain restrictions on transfer with respect to lock-up shares held by Sponsor and Hoya Topco, including a twelve (12) month lock-up of such shares in each case, subject to limited exceptions as contemplated thereby (including that Sponsor and Hoya Topco may each transfer: (a) fifty percent (50%) of their lock-up shares on the date that is six

(6) months following the Closing Date and (b) the remaining lock-up shares on any date, at least six (6) months after the Closing, on which (i) the price per lock-up share exceeds $15.00 per share for twenty (20) trading days within a thirty (30) day trading period and (ii) the average daily trading volume exceeds one (1) million shares of Vivid Seats PubCo common stock during such thirty (30) trading day period). The Stockholders’ Agreement also contains certain provisions intended to maintain, following the consummation of the business combination, Vivid Seats PubCo’s qualification as a “controlled company” within the meaning of Nasdaq Listing Rule 5615(c)(1). For more information about the Stockholders’ Agreement, see the section entitled “Proposal No. 1 — The Business Combination Proposal — Related Agreements — Stockholders’ Agreement.”

Tax Receivable Agreement.    The Transaction Agreement contemplates that, at the Closing, Vivid Seats PubCo will enter into a Tax Receivable Agreement with Hoya Intermediate, the TRA Holder Representative, Hoya Topco and the other TRA Holders. Pursuant to the Tax Receivable Agreement, Vivid Seats PubCo will generally be required to pay Hoya Topco and the other TRA Holders 85% of the amount of savings, if any, in U.S. federal, state, local, and foreign taxes that are based on, or measured with respect to, net income or profits, and any interest related thereto that Vivid Seats PubCo (and applicable consolidated, unitary, or combined subsidiaries thereof, if any and collectively the “Tax Group”) realizes, or is deemed to realize, as a result of certain tax attributes (the “Tax Attributes”), including:

existing tax basis in certain assets of Hoya Intermediate and certain of its direct or indirect subsidiaries, including assets that will eventually be subject to depreciation or amortization, once placed in service;

tax basis adjustments resulting from taxable exchanges of Intermediate Common Units (including any such adjustments resulting from certain payments made by Vivid Seats PubCo under the Tax Receivable Agreement) acquired by Vivid Seats PubCo from a TRA Holder pursuant to the terms of the Second A&R LLCA;

certain tax attributes of Blocker Corporations holding Intermediate Common Units that are acquired directly or indirectly by Vivid Seats PubCo pursuant to a Reorganization Transaction;

certain tax benefits realized by Vivid Seats PubCo as a result of certain U.S. federal income tax allocations of taxable income or gain away from Vivid Seats PubCo and to other members of Hoya Intermediate and deductions or losses to Vivid Seats PubCo and away from other members of Hoya Intermediate, in each case, as a result of the business combination; and

tax deductions in respect of portions of certain payments made under the Tax Receivable Agreement.

Unless waived by the parties to the Transaction Agreement, the Closing is subject to a number of conditions set forth in the Transaction Agreement, including, among others, receipt of the requisite stockholder approval of the Transaction Agreement, Plan of Merger and the Merger and the other Proposals as contemplated by this proxy statement/prospectus. For more information about the closing conditions to the business combination, see the section entitled “Proposal No. 1— The Business Combination Proposal — The Transaction Agreement — Conditions to the Closing of the Business Combination.”

The Transaction Agreement may be terminated at any time prior to the Closing upon agreement by Hoya Topco and Horizon, or by Hoya Topco or Horizon, acting alone, in specified circumstances. For more information about the termination rights under the Transaction Agreement, see the section entitled “Proposal No. 1 — The Business Combination Proposal — Termination.”

The proposed business combination involve numerous risks. For more information about these risks, please read “Risk Factors.”

Under Horizon’s amended and restated memorandum and articles of association, holders of public shares may elect to have their shares redeemed for cash at the applicable redemption price per share calculated in accordance with Horizon’s amended and restated memorandum and articles of association. As of December 31, 2020, this would have amounted to approximately $10.00 per share. If a holder exercises its redemption rights, then such holder will be exchanging its Horizon Class A ordinary shares for cash and will no longer own shares of Horizon. Such a holder will be entitled to receive cash for its public shares only if it properly demands redemption and delivers its shares (either physically or electronically) to our transfer agent in accordance with the procedures described herein. Notwithstanding the foregoing, a holder of the public shares, together with any affiliate of his or any other person with whom he is acting in concert or as a “group” (as defined in Section 13(d)(3) of the Exchange Act), will be restricted from seeking redemption rights with respect to more than 15% of the Horizon Class A ordinary shares included in the units sold in the IPO, which we refer to as the “15% threshold.” Accordingly, all public shares in excess of the 15% threshold beneficially owned by a public shareholder or group will not be redeemed for cash. Each redemption of Horizon Class A ordinary shares by Horizon’s public shareholders will decrease the amount in the Trust Account, which holds approximately $544 million as of December 31, 2020. In no event will Horizon redeem public shares in an amount that would cause its net tangible assets to be less than $5,000,001. See the section entitled “Extraordinary General Meeting of Horizon Shareholders — Redemption Rights.”

It is anticipated that, upon completion of the business combination and assuming no redemptions of shares of Horizon Class A ordinary shares in connection with the business combination, Vivid Seats PubCo’s ownership will be as follows: (a) Horizon’s public shareholders will own approximately 19.9% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class A common stock); (b) the PIPE Investors, including certain affiliates of the Sponsor, will own approximately 11.5% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class A common stock); (c) Sponsor (excluding affiliates of the Sponsor that are PIPE Investors) and other holders of the founder shares will own approximately 8.0% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class A common stock); and (d) Hoya Topco will own approximately 60.6% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class B common stock). In turn, Vivid Seats PubCo will hold approximately 39.4% of the Intermediate Common Units and Hoya Topco will hold approximately 60.6% of the Intermediate Common Units. These levels of ownership interest assume that no shares are elected to be redeemed in connection with the business combination. The PIPE Investors have agreed to purchase in the aggregate 22,500,000 shares of Vivid Seats Class A common stock, for approximately $225.0 million of gross proceeds, in the PIPE Subscription. In this proxy statement/prospectus, Horizon assumes that approximately $769.0 million of the gross proceeds from the PIPE Subscription and funds held in the Trust Account will be used to fund (i) the business combination, (ii) the partial repayment of our Term Loan Facilities to a net debt amount (consisting of long-term debt, less cash and cash equivalents) of approximately $132.1 million under both the no redemption scenario and maximum redemption scenario, and (iii) the payment of certain transaction expenses. The ownership percentage with respect to Vivid Seats PubCo does not take into account (A) warrants to purchase Horizon Class A ordinary shares that will be converted into Vivid Seats PubCo Warrants immediately following the business combination or other Vivid Seats PubCo Warrants issued in connection with the business combination or (B) the issuance of any shares upon completion of the business combination under the 2021 Plan. If the actual facts are different from these assumptions, the above levels of ownership interest will be different.

It is anticipated that, upon completion of the business combination, (a) Horizon’s public shareholders will own 12,966,144 Vivid Seats Public IPO Warrants and (b) Sponsor will own 5,166,666 Vivid Seats Public IPO Warrants (and does not include the Horizon $10.00 Exercise Warrants, the Horizon $15.00

Exercise Warrants and the Vivid Seats Private Placement IPO Warrants). Pursuant to the Exchange Agreement, Sponsor will receive (i) warrants to purchase 17,000,000 shares of Horizon Class A ordinary shares at an exercise price of $10.00 per share (the “Horizon $10.00 Exercise Warrants”), (ii) warrants to purchase 17,000,000 shares of Horizon Class A ordinary shares at an exercise of $15.00 per share (the “Horizon $15.00 Exercise Warrants”) and (iii) 50,000 shares of Horizon Class A ordinary shares, as more particularly set forth therein. Horizon’s public shareholders and warrant holders will receive no monetary consideration in connection with the completion of the business combination. At the Effective Time, by virtue of the Merger and without any action on the part of any holder of Horizon ordinary shares or warrant of Horizon, (i) each Horizon ordinary share that is issued and outstanding immediately prior to the Effective Time (other than any Horizon ordinary shares held in the treasury of Horizon) will be cancelled and converted into one share of Vivid Seats Class A common stock and (ii) each Horizon Warrant that is issued and outstanding immediately prior to the Effective Time will be converted into a corresponding Vivid Seats PubCo Warrant exercisable for one share of Vivid Seats Class A common stock at an exercise price set forth in the applicable warrant agreement. Based on an assumed value of a share of Vivid Seats Class A common stock of $10.00 and assuming no redemptions of Horizon Class A ordinary shares in connection with the business combination, the aggregate value of consideration holders of Horizon ordinary shares will receive for their shares pursuant to the business combination is approximately $389 million. Holders of Horizon’s Warrants will receive Vivid Seats PubCo Warrants that will have an exercise price of $11.50 per share; however, depending on the price of Vivid Seats Class A common stock following the business combination, such warrants may have no value and may expire worthless or otherwise be redeemed in accordance with their terms.

Horizon’s board of directors considered various factors in determining whether to approve the Transaction Agreement and the business combination. For more information about Horizon’s decision-making process, see the section entitled “Proposal No. 1 — The Business Combination Proposal — Horizon’s Board of Directors’ Reasons for the Approval of the Business Combination.”

In addition to voting on the proposal to approve and adopt the Transaction Agreement and the business combination (the “Business Combination Proposal”) at the extraordinary general meeting, Horizon’s shareholders will also be asked to vote on:

a proposal (the “Merger Proposal”) to approve, as a special resolution, the Plan of Merger annexed to the Transaction Agreement and attached to this proxy statement/prospectus as Annex K and to authorize the merger (the “Merger”) of Horizon with and into Vivid Seats PubCo, upon which the separate corporate existence of Horizon will cease and Vivid Seats PubCo will become the surviving corporation (the “Surviving Corporation”);

the following three separate proposals (collectively, the “Organizational Documents Proposals”) to approve the following material differences between Horizon’s amended and restated memorandum and articles of association and the amended and restated certificate of incorporation of Vivid Seats PubCo (the “Vivid Seats PubCo Amended and Restated Charter”) and the amended and restated bylaws of Vivid Seats PubCo (the “Vivid Seats PubCo Amended and Restated Bylaws”) that will be the certificate of incorporation and bylaws of Vivid Seats PubCo following the Merger:

a proposal to authorize the change in the authorized capital stock of Horizon from 400,000,000 Horizon Class A ordinary shares, par value $0.0001 per share (the “Horizon Class A ordinary shares”), 40,000,000 shares of Horizon Class B ordinary shares, par value $0.0001 per share (the “Horizon Class B ordinary shares”), and 1,000,000 preference shares, par value $0.0001 per share, to 500,000,000 shares of Class A common stock, par value $0.0001 per share, of Vivid Seats PubCo (the “Vivid Seats Class A common stock”), 250,000,000 shares of Class B common stock, par value $0.0001 per share, of Vivid Seats PubCo (the “Vivid Seats Class B common stock”) and 50,000,000 shares of preferred stock, par value $0.0001 per share, of Vivid Seats PubCo;

a proposal to authorize that certain provisions of the Vivid Seats PubCo Amended and Restated Charter and certain provisions of the Vivid Seats PubCo Amended and Restated Bylaws, in each case, will be subject to the Stockholders’ Agreement; and

a proposal to authorize all other changes in connection with the replacement of Horizon’s amended and restated memorandum and articles of association with the Vivid Seats PubCo Amended and Restated Charter and the Vivid Seats PubCo Amended and Restated Bylaws as part of the Merger (copies of which are attached to this proxy statement/prospectus as Annex C and Annex D, respectively), including (a) changing the corporate name from “Horizon Acquisition Corporation” to “Vivid Seats Inc.,” (b) granting an explicit waiver regarding corporate opportunities to certain “exempted persons” (including each stockholder or director of Vivid Seats PubCo or any of its subsidiaries, other than a director that is an officer or employee of Vivid Seats PubCo or any of its subsidiaries in his or her capacity as such), (c) adopting Delaware as the exclusive forum for certain stockholder litigation, (d) electing not to be governed by Section 203 of the DGCL and (e) removing certain provisions related to Horizon’s status as a blank check company that will no longer be applicable upon consummation of the business combination, all of which Horizon’s board of directors believes is necessary to adequately address the needs of Vivid Seats PubCo after the business combination;

a proposal to approve, for purposes of complying with NYSE Listing Rule 312.03, the issuance of shares of Vivid Seats PubCo in connection with the business combination and the PIPE Subscription (the “NYSE Proposal”); and

a proposal to approve the adjournment of the extraordinary general meeting to a later date or dates, if necessary or appropriate, to permit further solicitation and vote of proxies in the event that there are insufficient votes for, or otherwise in connection with, the approval of the Business Combination Proposal, the Merger Proposal, the Organizational Documents Proposals and the NYSE Proposal (the “Adjournment Proposal” and, together with the Business Combination Proposal, the Merger Proposal, the Organizational Documents Proposals and the NYSE Proposal, the “Proposals”).

Why am I receiving this proxy statement/prospectus?

Horizon shareholders are being asked to consider and vote upon, among other things, a proposal to (a) approve and adopt the Transaction Agreement, pursuant to which, among other transactions, Horizon will merge with and into Vivid Seats PubCo, upon which the separate corporate existence of Horizon will cease and Vivid Seats PubCo will be the surviving corporation, and (b) approve such Merger and the other transactions contemplated by the Transaction Agreement (the “Business Combination Proposal”).

What is being voted on at the extraordinary general meeting?

Below are the proposals on which Horizon shareholders will vote at the extraordinary general meeting.

Proposal No. 1 — The Business Combination Proposal — To consider and vote upon a proposal to (a) approve and adopt the Transaction Agreement pursuant to which, among other transactions, Horizon will merge with and into Vivid Seats PubCo, upon which the separate corporate existence of Horizon will cease and Vivid Seats PubCo will become the surviving corporation, and (b) approve the business combination.

Proposal No. 2 — The Merger Proposal — To consider and vote upon a proposal to approve, as a special resolution, the Plan of Merger annexed to the Transaction Agreement and attached to this proxy statement/prospectus as Annex K and to authorize the merger of Horizon with and into Vivid Seats PubCo, upon which the separate corporate existence of Horizon will cease and Vivid Seats PubCo will become the surviving corporation.

The Organizational Documents Proposals — To consider and vote upon the following three separate proposals to approve the following material differences between Horizon amended and restated memorandum and articles of association and the Vivid Seats PubCo Amended and Restated Charter and the Vivid Seats PubCo Amended and Restated Bylaws that will be the certificate of incorporation and bylaws of Vivid Seats PubCo following the Merger:

Proposal No. 3 — Organizational Documents Proposal A — To authorize the change in the authorized capital stock of Horizon from 400,000,000 Horizon Class A ordinary shares, 40,000,000 shares of Horizon Class B ordinary shares, and 1,000,000 preference shares, par value $0.0001 per share, to 500,000,000 shares of Vivid Seats Class A common stock, 250,000,000 shares of Vivid Seats Class B common stock and 50,000,000 shares of preferred stock, par value $0.0001 per share, of Vivid Seats PubCo.

Proposal No. 4 — Organizational Documents Proposal B — To authorize that certain provisions of the Vivid Seats PubCo Amended and Restated Charter and certain provisions of the Vivid Seats PubCo Amended and Restated Bylaws, in each case, will be subject to the Stockholders’ Agreement.

Proposal No. 5 — Organizational Documents Proposal C — To authorize all other changes in connection with the replacement of Horizon’s amended and restated memorandum and articles of association with the Vivid Seats PubCo Amended and Restated Charter and the Vivid Seats PubCo Amended and Restated Bylaws as part of the Merger (copies of which are attached to this proxy statement/prospectus as Annex C and Annex D, respectively), including (a) changing the corporate name from “Horizon Acquisition Corporation” to “Vivid Seats Inc.,” (b) granting an explicit waiver regarding corporate opportunities to certain “exempted persons” (including each stockholder or director of Vivid Seats PubCo or any of its subsidiaries, other than a director that is an officer or employee of Vivid Seats PubCo or any of its subsidiaries in his or her capacity as such), (c) adopting Delaware as the exclusive forum for certain stockholder litigation, (d) electing not to be governed by Section 203 of the DGCL and (e) removing certain provisions related to Horizon’s status as a blank check company that will no longer be applicable upon consummation of the business combination, all of which Horizon’s board of directors believes is necessary to adequately address the needs of Vivid Seats PubCo after the business combination.

Proposal No. 6 — The NYSE Proposal — To consider and vote upon a proposal to approve, for purposes of complying with NYSE Listing Rule 312.03, the issuance of shares of Vivid Seats PubCo in connection with the business combination and the PIPE Subscription (the “NYSE Proposal”); and

Proposal No. 7 — The Adjournment Proposal — To consider and vote upon a proposal to approve the adjournment of the extraordinary general meeting to a later date or dates, if necessary or appropriate, to permit further solicitation and vote of proxies in the event that there are insufficient votes for, or otherwise in connection with, the approval of the Business Combination Proposal, the Merger Proposal, the Organizational Documents Proposals and the NYSE Proposal.

What happens if a substantial number of the public shareholders vote in favor of the Business Combination Proposal and exercise their redemption rights?

Horizon’s public shareholders may vote in favor of the business combination and still exercise their redemption rights. Accordingly, the business combination may be consummated even though the funds available from the Trust Account and the number of public shareholders are reduced as a result of redemptions by public shareholders. The Transaction Agreement provides that the cash proceeds from the Trust Account and PIPE Subscription (collectively, the “Transaction Proceeds”) must be at least $769.0 million. In the event that redemptions of Horizon Class A ordinary shares reduce the Transaction Proceeds to an amount below $769.0 million, Sponsor shall increase its commitment to the PIPE Subscription by a corresponding amount (the “Sponsor Backstop Commitment”). In the event that redemptions of Horizon Class A ordinary shares reduce the Transaction Proceeds to an amount below $380.0 million prior to consideration of the Sponsor Backstop Commitment, Sponsor is entitled to arrange for the purchase of additional shares of Horizon ordinary shares from third party investors at a price of $10.00 per share with prior written consent of Hoya Topco. Accordingly, even if all public shareholders entitled to redemption elect to have their shares redeemed, the business combination may still occur. In addition, in no event will we redeem public shares in an amount that would cause Horizon’s net tangible assets (as determined in accordance with Rule 3a51-1(g)(1) of the Exchange Act) to be less than $5,000,001. It is anticipated that, upon completion of the business combination and assuming no redemptions of shares of Horizon Class A ordinary shares in connection with the business combination, Vivid Seats PubCo’s ownership will be as follows: (1) Horizon public shareholders will own approximately 19.9% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class A common stock); (2) the PIPE Investors, including certain affiliates of Sponsor, will own approximately 11.5% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class A common stock); (3) Sponsor (excluding affiliates of the Sponsor that are PIPE Investors) and the other holders of the founder shares will own approximately 8.0% of Vivid Seats PubCo’s outstanding common

Are the proposals conditioned on one another?

Yes. The Closing is conditioned on the approval of the Business Combination Proposal, the Merger Proposal, the Organizational Documents Proposals and the NYSE Proposal at the extraordinary general meeting. The Organizational Documents Proposals are conditioned on the approval of the Business Combination Proposal, the Merger Proposal and the NYSE Proposal. The Adjournment Proposal is not conditioned on the approval of any other proposal set forth in this proxy statement/prospectus.

Why is Horizon providing shareholders with the opportunity to vote on the business combination?

Under Horizon’s amended and restated memorandum and articles of association, Horizon must provide all holders of Horizon Class A ordinary shares with the opportunity to redeem their public shares upon the consummation of an initial business combination either in conjunction with a tender offer or in conjunction with a shareholder vote. For business and other reasons, Horizon has elected to provide its shareholders with the opportunity to have their public shares redeemed in connection with a shareholder vote rather than a tender offer. Therefore, Horizon is seeking to obtain the approval of its shareholders of the Business Combination Proposal in order to allow its public shareholders to effectuate redemptions of their public shares in connection with the Closing. The approval of Horizon’s shareholders of the Business Combination Proposal is also a condition to closing in the Transaction Agreement. Holders of Horizon’s warrants are not entitled to vote on the business combination. Under Horizon’s amended and restated memorandum and articles of association, Horizon’s warrants do not have redemption rights in connection with the business combination.

What will happen in the business combination?

On April 21, 2021, Horizon, Sponsor, Vivid Seats PubCo, Hoya Topco and Hoya Intermediate entered into the Transaction Agreement, pursuant to which: (a) at least one day prior to the Merger, Sponsor and Horizon will effect the Exchange, (b) prior to the Merger, Hoya Topco and Vivid Seats will effect the Pre-Closing Restructuring (as defined in the Transaction Agreement), which will include the Class A Redemption and the Intermediate Merger, (c) Horizon will merge with and into Vivid Seats PubCo, upon which the separate corporate existence of Horizon will cease and Vivid Seats PubCo will become the surviving entity in the Merger, (d) the Second A&R LLCA will become effective, (e) Vivid Seats PubCo will purchase the Crescent Blockers in the Blocker Purchase, (f) Vivid Seats PubCo and Hoya Intermediate will consummate the Intermediate Contribution and Issuance, (g) Hoya Intermediate will redeem the Intermediate Common Units held by the Redeemed Crescent Parties in the Crescent Redemption, (h) Vivid Seats PubCo will issue Vivid Seats Class B common stock and warrants to purchase Vivid Seats Class B common stock to Hoya Topco in the Class B Issuance, and (i) Hoya Intermediate will contribute a portion of the fund received from Vivid Seats PubCo to Hoya Midco for repayment of a portion of its existing debt obligations.

What factors did Horizon’s board of directors consider in connection with its decision to recommend voting in favor of the business combination?

Horizon’s board of directors considered a variety of factors in connection with its decision to recommend voting in favor of the business combination. Some of these factors include, but are not limited to:

Strong Historical Financial Performance and Economic Model. Historical information regarding Hoya Intermediate and Vivid Seats PubCo’s business, financial performance, and results of operations;

Favorable Prospects for Future Growth and Financial Performance. Current information and forecast projections from Horizon and Vivid Seats PubCo’s management regarding (i) Hoya Intermediate and Vivid Seats PubCo’s business, prospects, financial condition, operations, technology, products, services, management, competitive position, and strategic business goals and objectives, (ii) general economic, industry, regulatory and financial market conditions and (iii) opportunities and competitive factors within Hoya Intermediate and Vivid Seats PubCo’s industry;

Differentiated Technology Platform. Best-in-class proprietary search algorithms focuses customer experience on event discovery and conversion and creates unique engine for generating new customers;

Compelling Valuation. The implied enterprise value in connection with the business combination of approximately $2.0 billion, which Horizon’s board of directors believes represents an attractive valuation relative to selected comparable companies;

World Class Management Team. Hoya Intermediate and Vivid Seats PubCo’s experienced management team, led by Stanley Chia, Hoya Intermediate and Vivid Seats PubCo’s Chief Executive Officer;

Potential for Future Accretive M&A. We believe that Hoya Intermediate and Vivid Seats PubCo are positioned as an attractive M&A platform opportunity as it continues to expand its offerings and geographic reach; and

Likelihood of Closing the Business Combination. The belief of the Horizon board of directors that an acquisition by Horizon has a reasonable likelihood of closing without potential issues under applicable antitrust and competition laws, or potential issues from any regulatory authorities.

What conditions must be satisfied to complete the business combination?

There are a number of closing conditions in the Transaction Agreement, including the approval by Horizon’s shareholders of the Business Combination Proposal, the Merger Proposal, the Organizational Documents Proposals and the NYSE Proposal. For a summary of the conditions that must be satisfied or waived prior to completion of the business combination, see the section entitled “Proposal No. 1 — The Business Combination Proposal — The Transaction Agreement — Conditions to the Closing of the Business Combination.”

How will Vivid Seats PubCo be managed and governed following the business combination?

The business and affairs of Vivid Seats PubCo will be managed under the direction of its board of directors. Following the Closing, the Vivid Seats Board will include nine (9) directors, one (1) of which will be the

How will Hoya Intermediate be managed and governed following the business combination?

The business and affairs of Hoya Intermediate will be managed under the direction of its board of managers. The Hoya Intermediate board of managers will initially consist of two individuals, one of which will be designated by Vivid Seats PubCo and one of which will be designated by Hoya Topco. For each matter presented to the board of managers of Hoya Intermediate, the Vivid Seats PubCo designee will be entitled to two (2) votes and the Hoya Topco designee will be entitled to one (1) vote. Immediately following the Closing, Vivid Seats PubCo’s Private Equity Owner will be able to designate the majority of the directors of the Vivid Seats Board and generally have control over the business and affairs of Vivid Seats PubCo. For more information regarding Vivid Seats PubCo’s Private Equity Owner’s controlling interest in Vivid Seats PubCo, see the section entitled “Risk Factors — Risks Related to Organizational Structure After the Business Combination — Vivid Seats PubCo’s Private Equity Owner will control us, and its interests may conflict with ours or yours in the future.”

Will Horizon obtain new financing in connection with the business combination?

Horizon entered into the Subscription Agreements with the PIPE Investors, pursuant to which, subject to the consummation of the business combination, the PIPE Investors have agreed to purchase an aggregate of 22,500,000 shares of Vivid Seats Class A common stock, in a private placement for a purchase price of $10.00 per share, for aggregate gross proceeds of $225.0 million; provided, however, that such subscription is subject to increase due to the Sponsor Backstop Commitment. The closings under the Subscription Agreements will occur after the Effective Time and substantially concurrently with the closing of the business combination. For more information about the Subscription Agreements, see the section entitled “Proposal No. 1 — The Business Combination Proposal — Related Agreements — PIPE Subscription Agreements.”

What equity stake will current Horizon shareholders, the PIPE Investors, the holders of the founder shares and Hoya Topco hold in Vivid Seats PubCo following the consummation of the business combination?

It is anticipated that, upon completion of the business combination and assuming no redemptions of Horizon Class A ordinary shares in connection with the business combination, Vivid Seats PubCo’s ownership will be as follows: (1) Horizon public shareholders will own approximately 19.9% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class A common stock); (2) the PIPE Investors, including certain affiliates of the Sponsor, will own approximately 11.5% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class A common stock); (3) Sponsor (excluding affiliates of Sponsor that are PIPE Investors) and the other holders of the founder shares will own approximately 8.0% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class A common stock); and (4) Hoya Topco will own approximately 60.6% of Vivid Seats PubCo’s outstanding common stock (which will be in the form of shares of Vivid Seats Class B common stock). In turn, Vivid Seats PubCo will indirectly hold approximately 39.4% of the Intermediate Common Units and Hoya Topco will hold approximately 60.6% of the Intermediate Common Units. In addition, Vivid Seats PubCo will hold 58,652,601 Hoya Intermediate Warrants, exercisable upon the exercise of Vivid Seats PubCo Warrants. These levels of ownership interest assume that no shares are elected to be redeemed in connection with the business combination. The PIPE Investors have agreed to purchase an aggregate of 22,500,000 shares of Vivid Seats Class A common stock, in a private placement for a purchase price of $10.00 per share, for aggregate gross proceeds of $225.0 million in the PIPE Subscription. In this proxy statement/prospectus, Horizon assumes that approximately $769.0 million of the gross proceeds from the PIPE Subscription and funds held in the Trust Account will be used to fund (i) the business combination, (ii) the partial repayment of our Term Loan Facilities to a net debt amount (consisting of long-term debt, less cash and cash equivalents) of approximately $132.1 million under both the no redemption scenario and maximum redemption scenario, and (iii) the payment of certain transaction expenses. The ownership percentage with respect to Vivid Seats

What are the material differences between Horizon’s amended and restated memorandum and articles of association and the Vivid Seats PubCo Amended and Restated Bylaws and Vivid Seats PubCo Amended and Restated Charter, which will be the organizational documents of Vivid Seats PubCo following the Merger as set forth in the Organizational Documents Proposals?

Horizon is asking its shareholders to approve the following material differences between Horizon’s amended and restated memorandum and articles of association and the Vivid Seats PubCo Amended and Restated Bylaws and Vivid Seats PubCo Amended and Restated Charter, which will be the certificate of incorporation and bylaws of Vivid Seats PubCo following the Merger: (1) an amendment to authorize the change in the authorized capital stock of Horizon from 400,000,000 Horizon Class A ordinary shares, 40,000,000 shares of Horizon Class B ordinary shares, and 1,000,000 preference shares, par value $0.0001 per share, to 500,000,000 shares of Vivid Seats Class A common stock, 250,000,000 shares of Vivid Seats Class B common stock and 50,000,000 shares of preferred stock, par value $0.0001 per share, of Vivid Seats PubCo; (2) an amendment to authorize that certain provisions of the Vivid Seats PubCo Amended and Restated Charter and certain provisions of the Vivid Seats PubCo Amended and Restated Bylaws, in each case, will be subject to the Stockholders’ Agreement; and (3) an amendment to authorize all other changes in connection with the replacement of Horizon’s amended and restated memorandum and articles of association with the Vivid Seats PubCo Amended and Restated Charter and the Vivid Seats PubCo Amended and Restated Bylaws as part of the Merger (copies of which are attached to this proxy statement/prospectus as Annex C and Annex D, respectively), including (a) changing the corporate name from “Horizon Acquisition Corporation” to “Vivid Seats Inc.,” (b) granting an explicit waiver regarding corporate opportunities to certain “exempted persons” (including each stockholder or director of Vivid Seats PubCo or any of its subsidiaries, other than a director that is an officer or employee of Vivid Seats PubCo or any of its subsidiaries in his or her capacity as such), (c) adopting Delaware as the exclusive forum for certain stockholder litigation, (d) electing not to be governed by Section 203 of the DGCL and (e) removing certain provisions related to Horizon’s status as a blank check company that will no longer be applicable upon consummation of the business combination, all of which Horizon’s board of directors believes is necessary to adequately address the needs of Vivid Seats PubCo after the business combination.

Why is Horizon proposing the NYSE Proposal?

Horizon is proposing the NYSE Proposal in order to comply with NYSE listing rules, which require shareholder approval prior to the issuance of common stock, or of securities convertible into or exercisable for common stock, if the number of shares of common stock to be issued is, or will be upon issuance, equal to or in excess of 20% of the number of shares of common stock outstanding before the issuance of the common stock or of securities convertible into or exercisable for common stock. In connection with the business combination, Horizon is seeking shareholder approval for the issuance of (subject to customary terms and conditions, including the Closing) of Vivid Seats Class A common stock and Vivid Seats Class B common stock in connection with the business combination and the PIPE Subscription. Because the number

What happens if I sell my Horizon Class A ordinary shares before the extraordinary general meeting?

The record date for the extraordinary general meeting is earlier than the date that the business combination is expected to be completed. If you transfer your Horizon Class A ordinary shares after the record date, but before the extraordinary general meeting, unless the transferee obtains from you a proxy to vote those shares, you will retain your right to vote at the extraordinary general meeting. However, you will not be able to seek redemption of your Horizon Class A ordinary shares because you will no longer be able to deliver them for cancellation upon the Closing in accordance with the provisions described herein. If you transfer your Horizon Class A ordinary shares prior to the record date, you will have no right to vote those shares at the extraordinary general meeting or redeem those shares for a pro rata portion of the proceeds held in the Trust Account.

What vote is required to approve the Proposals presented at the extraordinary general meeting?

Approval of the Business Combination Proposal, the Organizational Documents Proposals and the NYSE Proposal and the Adjournment Proposal requires the approval of an ordinary resolution under Cayman Islands law, being the affirmative vote of the holders of a majority of the votes cast by the then outstanding Horizon ordinary shares who, being present and entitled to vote at the extraordinary general meeting, vote at the extraordinary general meeting. Abstentions and broker non-votes will have no effect on the Business Combination Proposal, the Organizational Documents Proposals and the NYSE Proposal or the Adjournment Proposal.

May Sponsor or Horizon’s directors, officers, or advisors or their respective affiliates purchase shares in connection with the business combination?

In connection with the shareholder vote to approve the proposed business combination, Sponsor and Horizon’s directors, officers and advisors and their respective affiliates may privately negotiate transactions to purchase shares from shareholders who would have otherwise elected to have their shares redeemed in conjunction with a proxy solicitation pursuant to the proxy rules for a per share pro rata portion of the Trust Account. As of March 31, 2021, Sponsor and Horizon’s directors, officers and advisors and certain of their respective affiliates hold approximately 28.7% Horizon Class A ordinary shares and 100% of Horizon Class B ordinary shares. None of Sponsor or Horizon’s directors, officers or advisors or their respective affiliates will make any such purchases when they are in possession of any material non-public information not disclosed to the seller. Such a purchase would include a contractual acknowledgement that such shareholder, although still the record holder of Horizon’s shares, is no longer the beneficial owner thereof and therefore agrees not to exercise its redemption rights, and could include a contractual provision that directs such shareholder to vote such shares in a manner directed by the purchaser. In the event that Sponsor or Horizon’s directors, officers or advisors or their respective affiliates purchase shares in privately negotiated transactions from public shareholders who have already elected to exercise their redemption rights, such selling shareholders would be required to revoke their prior elections to redeem their shares. Any such privately negotiated purchases may be effected at purchase prices that are below or in excess of the per share pro rata portion of the Trust Account.

How many votes do I have at the extraordinary general meeting?

Horizon’s shareholders are entitled to one vote at the extraordinary general meeting for each Horizon Class A ordinary share or Horizon Class B ordinary share held of record as of             , 2021, the record date for the extraordinary general meeting. As of the close of business on the record date, there were a combined              outstanding Horizon Class A ordinary shares and Horizon Class B ordinary shares.

What constitutes a quorum at the extraordinary general meeting?

A quorum of Horizon shareholders is necessary to hold a valid meeting. A quorum will be present at the extraordinary general meeting if the holders of a majority of the issued and outstanding Horizon ordinary shares entitled to vote at the extraordinary general meeting are represented in person or by proxy. As of the record date for the extraordinary general meeting,                Horizon ordinary shares would be required to achieve a quorum.

How will Sponsor and Horizon’s directors and officers vote?

In connection with the IPO, Horizon entered into an agreement with Sponsor and each of Horizon’s directors and officers, pursuant to which each agreed to vote any Horizon Class A ordinary shares and Horizon Class B ordinary shares owned by them in favor of the Business Combination Proposal. Currently, Sponsor and Horizon’s directors and officers own approximately 28.7% of Horizon’s issued and outstanding Horizon Class A ordinary shares and 100% of Horizon Class B ordinary shares, in the aggregate, including all of the founder shares.

What interests do the current officers and directors have in the business combination?

In considering the recommendation of Horizon’s board of directors to vote in favor of the business combination, shareholders should be aware that, aside from their interests as shareholders, Sponsor and certain of Horizon’s directors and officers have interests in the business combination that are different from, or in addition to, those of other shareholders generally. Horizon’s directors were aware of and considered these interests, among other matters, in evaluating the business combination, and in recommending to shareholders that they approve the business combination. Shareholders should take these interests into account in deciding whether to approve the business combination. These interests include, among other things:

the fact that Sponsor has agreed not to redeem any Class A ordinary shares held by it in connection with a shareholder vote to approve a proposed initial transaction;

the fact that Sponsor paid an aggregate of $155 million for 15,500,000 Horizon Class A ordinary shares (after giving effect to forfeitures in connection with the underwriters’ overallotment option being reduced or not exercised) (none of which were transferred to Horizon’s independent directors and none of which were transferred to Horizon’s strategic advisors) and such securities may have a higher value at the time of the business combination;

the fact that Sponsor paid an aggregate of $25,000 for 13,599,608 Horizon Class B ordinary shares (after giving effect to forfeitures in connection with the underwriters’ overallotment option being reduced or not exercised) (the “Sponsor Shares”) (none of which were transferred to Horizon’s independent directors and none of which were transferred to Horizon’s strategic advisors) and such securities may have a higher value at the time of the business combination;

the fact that Sponsor paid an aggregate of $9.78 million for the 6,519,791 Horizon IPO Private Placement Warrants currently owned by Sponsor, and such warrants will expire worthless if a transaction is not consummated by August 25, 2022;

the fact that Sponsor and Horizon’s other current officers and directors have agreed to waive their rights to liquidating distributions from the Trust Account with respect to any Sponsor Shares held by them if Horizon fails to complete an initial transaction by August 25, 2022;

the fact that the Registration Rights Agreement will be entered into by Horizon;

the fact that, at the option of Sponsor, any amounts outstanding under any loan made by Sponsor or any of its affiliates to Horizon in an aggregate amount of up to $1,500,000 may be converted into warrants to purchase Vivid Seats Class A common stock in connection with the consummation of the business combination;

the right of Sponsor to hold shares of Vivid Seats Class A common stock, as well as Vivid Seats PubCo Warrants, following the business combination, subject to certain lock-up periods;

the continued indemnification of Horizon’s existing directors and officers and the continuation of Horizon’s directors’ and officers’ liability insurance after the business combination (i.e., a “tail policy”);

the fact that Sponsor and Horizon’s officers and directors will not be reimbursed for any out-of-pocket expenses if an initial transaction is not consummated by August 25, 2022;

the fact that if the Trust Account is liquidated, including in the event Horizon is unable to complete an initial transaction by August 25, 2022, Sponsor has agreed to indemnify Horizon to ensure that the proceeds in the Trust Account are not reduced below $10.00 per public share, or such lesser per public share amount as is in the Trust Account on the liquidation date, by the claims of prospective target businesses with which Horizon has entered into an acquisition agreement or claims of any third party for services rendered or products sold to Horizon, but only if such a vendor or target business has not executed a waiver of any and all rights to seek access to the Trust Account;

the fact that Horizon may be entitled to distribute or pay over funds held by Horizon outside the Trust Account to Sponsor or any of its affiliates prior to the Closing;

the fact that Hoya Intermediate shall pay Sponsor $11.7 million in cash at Closing in consideration for the Sponsor Backstop Commitment; and

the fact that Sponsor will enter into the Exchange Agreement, pursuant to which all Horizon Class B ordinary shares will be exchanged for (i) warrants to purchase 17,000,000 shares of Horizon Class A ordinary shares at an exercise price of $10.00 per share (the “Horizon $10.00 Exercise Warrants”), (ii) warrants to purchase 17,000,000 shares of Horizon Class A ordinary shares at an exercise of $15.00 per share (the “Horizon $15.00 Exercise Warrants”) and (iii) 50,000 shares of Horizon Class A ordinary shares, as more particularly set forth in the Exchange Agreement.

What happens if I vote against the Business Combination Proposal?

Under Horizon’s amended and restated memorandum and articles of association, if the Business Combination Proposal is not approved and Horizon does not otherwise consummate an alternative business combination by August 25, 2022, unless further extended, Horizon will be required to dissolve and liquidate the Trust Account by returning the then-remaining funds in such account to Horizon’s public shareholders.

Do I have redemption rights?

If you are a holder of public shares, you may elect to have your public shares redeemed for cash at the applicable redemption price per share equal to the quotient obtained by dividing (a) the aggregate amount on deposit in the Trust Account as of two (2) business days prior to the Closing, including interest not previously released to Horizon to pay its franchise and income taxes, by (b) the total number of Horizon Class A ordinary shares included as part of the units sold in the IPO and which remain outstanding; provided that Horizon will not redeem any public shares to the extent that such redemption would result in

Will how I vote affect my ability to exercise redemption rights?

No. You may exercise your redemption rights whether you vote your Horizon Class A ordinary shares for or against or abstain from voting on the Business Combination Proposal or any other proposal described in this proxy statement/prospectus. As a result, the business combination can be approved by shareholders who will redeem their shares and no longer remain shareholders.

How do I exercise my redemption rights?

In order to exercise your redemption rights, you must (i) if you hold your Horizon Class A ordinary shares through units, elect to separate your units into the underlying public shares and Horizon IPO Public Warrants prior to exercising your redemption rights with respect to the public shares and (ii) prior to 5:00 p.m., Eastern Daylight time, on                , 2021 (two (2) business days before the extraordinary general meeting), tender your shares physically or electronically and submit a request in writing that Horizon redeem your public shares for cash to Continental Stock Transfer & Trust Company, Horizon’s transfer agent, at the following address:

What are the U.S. federal income tax consequences of exercising my redemption rights?

We expect that a U.S. Holder (as defined in “U.S. Federal Income Tax Considerations — U.S. Holders”) that exercises its redemption rights to receive cash from the trust account in exchange for its public shares will generally be treated as selling such public shares resulting in the recognition of capital gain or loss. There may be certain circumstances in which the redemption may be treated as a distribution for U.S. federal income tax purposes depending on the amount of public shares that such U.S. Holder owns or is deemed to own (including through the ownership of Horizon IPO Public Warrants) prior to and following the redemption. For a more complete discussion of the U.S. federal income tax considerations of an exercise of redemption rights, see “U.S. Federal Income Tax Considerations.”

What are the U.S. federal income tax consequences of the Merger?

As discussed more fully under “U.S. Federal Income Tax Considerations,” the Merger should constitute a tax-deferred reorganization within the meaning of Section 368(a)(1)(F) of the U.S. Internal Revenue Code of 1986, as amended (the “Code”). However, due to the absence of direct guidance on the application of

a U.S. Holder that holds public shares that have a fair market value of less than $50,000 on the date of the Merger generally will not recognize any gain or loss and will not be required to include any part of Horizon’s earnings in income;

a U.S. Holder that holds public shares that have a fair market value of $50,000 or more and that, on the date of the Merger, owns (actually and constructively) less than 10% of the total combined voting power of all classes of Horizon’s stock entitled to vote and less than 10% of the total value of all classes of Horizon’s stock generally will recognize gain (but not loss) on the exchange of public shares for shares of Class A common stock pursuant to the Merger. As an alternative to recognizing gain, such U.S. Holder may file an election to include in income as a deemed dividend the “all earnings and profits amount” (as defined in the Treasury Regulations under Section 367(b) of the Code) attributable to its public shares provided certain other requirements are satisfied; and

a U.S. Holder that holds public shares having a fair market value of $50,000 or more and that, on the date of the Merger, owns (actually or constructively) 10% or more of the total combined voting power of all classes of Horizon’s stock entitled to vote or 10% or more of the total value of all classes of Horizon’s stock generally will be required to include in income as a deemed dividend the “all earnings and profits amount” attributable to its public shares provided certain other requirements are satisfied. Any such U.S. Holder that is a corporation may, under certain circumstances, effectively be exempt from taxation on a portion or all of the deemed dividend pursuant to Section 245A of the Code (commonly referred to as the participation exemption).

If I am a warrant holder, can I exercise redemption rights with respect to my warrants?

No. The holders of Horizon’s warrants have no redemption rights with respect to such warrants.

Do I have appraisal rights if I object to the proposed business combination?

Under Section 239 of the CICA, the holders of Horizon public shares will not have appraisal or dissenter rights in connection with the business combination, including in connection with the Merger. Holders of public shares should consult their Cayman Islands legal counsel regarding their rights under the CICA.

What happens to the funds deposited in the Trust Account after the Closing?

If the Business Combination Proposal is approved, Horizon intends to use a portion of the funds held in the Trust Account to pay (i) a portion of Horizon’s aggregate costs, fees and expenses in connection with the consummation of the business combination, (ii) tax obligations and advisory fees and (iii) for any redemptions of public shares. The remaining balance in the Trust Account will be used for: (i) together with proceeds received from the PIPE Subscription, the repayment of a portion of outstanding debt (held at a subsidiary of Vivid Seats PubCo) and (ii) general corporate purposes. See the section entitled “Proposal No. 1 — The Business Combination Proposal” for additional information.

What happens if the business combination is not consummated or is terminated?

There are certain circumstances under which the Transaction Agreement may be terminated. See the section entitled “Proposal No. 1 — The Business Combination Proposal — The Transaction Agreement — Termination” for additional information regarding the parties’ specific termination rights. In accordance with Horizon’s existing amended and restated memorandum and articles of association, if an initial business combination is not consummated by August 25, 2022, unless extended, Horizon will (i) cease all operations except for the purpose of winding up, (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the public shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest (which interest shall be net of taxes payable and up to $100,000 of interest to pay dissolution expenses), divided by the number of then issued and outstanding public shares, which redemption will completely extinguish public shareholders’ rights as shareholders (including the right to receive further liquidation distributions, if any) and (iii) as promptly as reasonably possible following such redemption, subject to the approval of Horizon’s remaining shareholders and board of directors, liquidate and dissolve, subject, in each case, to Horizon’s obligations under Cayman Islands law to provide for claims of creditors and the other requirements of applicable law.

When is the business combination expected to be consummated?

It is currently anticipated that the business combination will be consummated promptly following the extraordinary general meeting of Horizon shareholders to be held on             , 2021; provided that all the requisite shareholder approvals are obtained and other conditions to the Closing have been satisfied or waived. For a description of the conditions for the completion of the business combination, see the section entitled “Proposal No. 1 — The Business Combination Proposal — The Transaction Agreement — Conditions to the Closing of the Business Combination.”

What do I need to do now?

You are urged to read carefully and consider the information contained in this proxy statement/prospectus, including “Risk Factors” and the annexes, and to consider how the business combination will affect you as a

How do I vote?

If you were a holder of record of Horizon Class A ordinary shares or Horizon Class B ordinary shares on             , 2021, the record date for the extraordinary general meeting of Horizon shareholders, you may vote with respect to the proposals in person at the extraordinary general meeting or by completing, signing, dating and returning the enclosed proxy card in the postage-paid envelope provided. If you hold your shares in “street name,” which means your shares are held of record by a broker, bank or other nominee, you should follow the instructions provided by your broker, bank or nominee to ensure that votes related to the shares you beneficially own are properly counted. In this regard, you must provide the record holder of your shares with instructions on how to vote your shares or, if you wish to attend the extraordinary general meeting and vote in person, obtain a proxy from your broker, bank or nominee.

What will happen if I abstain from voting or fail to vote at the extraordinary general meeting?

At the extraordinary general meeting, Horizon will count a properly executed proxy marked “ABSTAIN” with respect to a particular proposal as present for purposes of determining whether a quorum is present. For purposes of approval, failure to vote or an abstention will have no effect on the Proposals.

What will happen if I sign and submit my proxy card without indicating how I wish to vote?

Signed and dated proxies received by Horizon without an indication of how the shareholder intends to vote on a proposal will be voted “FOR” each proposal presented to the shareholders.

If I am not going to attend the extraordinary general meeting in person, should I submit my proxy card instead?

Yes. Whether you plan to attend the extraordinary general meeting or not, please read the enclosed proxy statement/prospectus carefully, and vote your shares by completing, signing, dating and returning the enclosed proxy card in the postage-paid envelope provided.

If my shares are held in “street name,” will my broker, bank or nominee automatically vote my shares for me?

No. Under the rules of various national and regional securities exchanges, your broker, bank, or nominee cannot vote your shares with respect to non-discretionary matters unless you provide instructions on how to vote in accordance with the information and procedures provided to you by your broker, bank, or nominee. Horizon believes the proposals presented to the shareholders will be considered non-discretionary and therefore your broker, bank, or nominee cannot vote your shares without your instruction. Your bank, broker, or other nominee can vote your shares only if you provide instructions on how to vote. You should instruct your broker to vote your shares in accordance with directions you provide.

May I change my vote after I have submitted my executed proxy card?

Yes. You may change your vote by sending a later-dated, signed proxy card to Horizon’s secretary at the address listed below so that it is received by Horizon’s secretary prior to the extraordinary general meeting or attend the extraordinary general meeting in person and vote. You also may revoke your proxy by sending a notice of revocation to Horizon’s secretary, which must be received prior to the extraordinary general meeting.

What should I do if I receive more than one set of voting materials?

You may receive more than one set of voting materials, including multiple copies of this proxy statement/prospectus and multiple proxy cards or voting instruction cards. For example, if you hold your shares in more than one brokerage account, you will receive a separate voting instruction card for each brokerage account in which you hold shares. If you are a holder of record and your shares are registered in more than one name, you will receive more than one proxy card. Please complete, sign, date and return each proxy card and voting instruction card that you receive in order to cast your vote with respect to all of your shares.

Who can help answer my questions?

If you have questions about the proposals or if you need additional copies of the proxy statement/prospectus or the enclosed proxy card you should contact Horizon’s Secretary at             .

Who will solicit and pay the cost of soliciting proxies?

Horizon will pay the cost of soliciting proxies for the extraordinary general meeting. Horizon has engaged              (the “Solicitation Agent”), to assist in the solicitation of proxies for the extraordinary general meeting. Horizon has agreed to pay the Solicitation Agent a fee of $                , plus disbursements. Horizon will reimburse the Solicitation Agent for reasonable out-of-pocket expenses and will indemnify the Solicitation Agent and its affiliates against certain claims, liabilities, losses, damages and expenses. Horizon will also reimburse banks, brokers and other custodians, nominees and fiduciaries representing beneficial owners of Horizon Class A ordinary shares and Horizon Class B ordinary shares their expenses in forwarding soliciting materials to beneficial owners of Horizon Class A ordinary shares and Horizon Class B ordinary shares and in obtaining voting instructions from those owners. Horizon’s directors, officers and employees may also solicit proxies by telephone, by facsimile, by mail, on the Internet or in person. They will not be paid any additional amounts for soliciting proxies.

the impact of any lingering economic downturn or recession resulting from the pandemic, including without limitation any reduction in discretionary spending or confidence for both buyers and sellers, that would result in a decline in ticket sales and attendance;

a reduction in the profitability of our operations when concert, sporting and theater events resume, due to governmental restrictions or safety precautions and protocols voluntarily undertaken, such as the potential that venues may not be able to be filled to capacity due to spacing and social distancing limitations, which could limit the number of tickets sold;

the impact on our workforce, which may include the loss of key personnel as employees find other employment and lowered employee morale or inability to replace hourly/seasonal workforce, all of which may negatively impact our ability to capitalize on opportunities and conduct our operations in the future;

potential decreased willingness or ability for artists to tour due to varying restrictions across jurisdictions, including the possibility that national or sub-national borders are closed to travel, which could reduce the demand for our services;

potential changes to consumer preferences for consumption of live music, sporting or theater events due to fear of, or restrictions on, large gatherings;

loss of ticketing sales due to the economic impacts of the pandemic whereby certain venue operators are no longer in operation, reducing the number of events our marketplace can serve;

the inability to pursue expansion opportunities or acquisitions due to capital constraints;

the future availability or increased cost of insurance coverage; and

the incurrence of additional expenses related to compliance, precautions and management of our company during and after the pandemic.

competitors’ offerings that may include more favorable terms or pricing;

technological changes and innovations that we are unable to adopt or are late in adopting that offer more attractive alternatives than we currently offer, which may lead to a loss of ticket sales or lower ticket fees;

other entertainment options or ticket inventory selection and variety that we do not offer; and

increased pricing in the primary ticket marketplace, which could result in reduced profits for secondary ticket sellers and reduced demand for our services.

using a significant portion of our available cash;

issuing equity securities, which would dilute current stockholders’ percentage ownership;

incurring substantial debt;

incurring or assuming contingent liabilities, known or unknown;

incurring amortization expenses related to intangibles; and

incurring large accounting write-offs or impairments.

integrating the operations, financial reporting, technologies and personnel of acquired companies, including establishing and maintaining a system of internal controls appropriate for a public company environment;

managing geographically dispersed operations;

the diversion of management’s attention from other business concerns;

the inherent risks in entering markets or lines of business in which we have either limited or no direct experience;

the potential loss of key employees, customers and strategic partners of acquired companies; and