As filed with the United States Securities and Exchange Commission on May 12, 2021

Registration No. 333-252374

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

_____________________________

AMENDMENT NO. 3

TO FORM S-4
REGISTRATION STATEMENT UNDER
THE SECURITIES ACT OF 1933

_____________________________

THUNDER BRIDGE II SURVIVING PUBCO, INC.

(Exact name of registrant as specified in its charter)

____________________________

Delaware*		6770		N/A
(State or Other Jurisdiction of Incorporation or Organization)		(Primary Standard Industrial Classification Code Number)		(I.R.S. Employer Identification No.)

____________________________

9912 Georgetown Pike
Suite D203
Great Falls, Virginia 22066
Telephone: (202) 431-0507
(Address, including zip code and telephone number, including area code, of registrant’s principal executive offices)

____________________________

Gary A. Simanson
President and Chief Executive Officer
Thunder Bridge II Surviving Pubco, Inc.
9912 Georgetown Pike
Suite D203
Great Falls, Virginia 22066
(202) 431-0507
(Name, address, including zip code and telephone number, including area code, of agent for service)

_____________________________

Copies to:

Jonathan H. Talcott
E. Peter Strand
Nelson Mullins Riley &
Scarborough LLP
101 Constitution Avenue, NW,
Suite 900
Washington, DC 20001
(202) 689-2800

Douglas S. Ellenoff, Esq.
Stuart Neuhauser, Esq.
Ellenoff Grossman & Schole LLP
1345 Avenue of the Americas
New York, NY 10105
(212) 370-1300

Mitchell S. Nussbaum, Esq.
Giovanni Caruso, Esq.
Loeb & Loeb LLP
345 Park Avenue
New York, NY 10154
(212) 407-4000

_____________________________

Approximate date of commencement of proposed sale to the public: As soon as practicable after (i) this registration statement is declared effective and (ii) upon completion of the applicable transactions described in the enclosed proxy statement/prospectus.

If the securities being registered on this Form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box: ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering: ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering: ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer”, “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

		Large accelerated filer ☐		Accelerated filer ☐
		Non-accelerated ☒		Smaller reporting company ☒
				Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer) ☐

Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer) ☐

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the Registration Statement shall become effective on such date as the SEC, acting pursuant to Section 8(a), may determine.

After giving effect to the Domestication and Business Combination described herein, by operation of Rule 12g-3 under the Securities Exchange Act of 1934, the Registrant will be the successor issuer to Thunder Bridge II and will succeed to the attributes of Thunder Bridge II as the Registrant.

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* Upon closing of the business combination referred to in the proxy statement/prospectus within this registration statement, the name of the registrant is expected to change to indie Semiconductor, Inc.

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The information in this proxy statement/prospectus is not complete and may be changed. Thunder Bridge II Surviving Pubco, Inc. may not issue the securities offered by this proxy statement/prospectus until the registration statement filed with the Securities and Exchange Commission, of which this proxy statement/prospectus is a part, is declared effective. This proxy statement/prospectus does not constitute an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale of these securities is not permitted.

PRELIMINARY PROXY STATEMENT/PROSPECTUS — SUBJECT TO COMPLETION, DATED MAY 12, 2021

PROXY STATEMENT FOR EXTRAORDINARY GENERAL MEETING OF THUNDER BRIDGE ACQUISITION II, LTD.

AND

PROSPECTUS FOR SHARES OF CLASS A COMMON STOCK AND WARRANTS OF THUNDER BRIDGE II SURVIVING PUBCO, INC.

Proxy Statement/Prospectus dated , 2021
and first mailed to shareholders on or about , 2021

To the Shareholders of Thunder Bridge Acquisition II, Ltd.:

On behalf of the board of directors of Thunder Bridge Acquisition II, Ltd. (“Thunder Bridge II”), we are pleased to enclose the proxy statement/prospectus relating to the proposed business combination of Thunder Bridge II and Ay Dee Kay, LLC d/b/a indie Semiconductor (“indie,”) pursuant to a Master Transactions Agreement dated effective as of December 14, 2020 (as may be further amended or supplemented from time to time, the “MTA”) among Thunder Bridge II Surviving Pubco, Inc. (“Surviving Pubco”), Thunder Bridge II, indie and certain other parties to the MTA. It is proposed that, simultaneously with the effectiveness of the Business Combination (the “Closing”), among other things, (1) Thunder Bridge II will transfer by way of continuation and domesticate from the Cayman Islands as an exempted company to the State of Delaware as a corporation (the “Domestication”), (2) a merger subsidiary of Surviving Pubco will merge with and into Thunder Bridge II pursuant to which Thunder Bridge II equity holders will receive corresponding shares and warrants of Surviving Pubco, with Surviving Pubco continuing as the successor public company to Thunder Bridge II and will change its name to indie Semiconductor, Inc., (3) a merger subsidiary of Surviving Pubco will merge with and into indie, with indie continuing as the surviving limited liability company (the Domestication, the mergers and the transactions contemplated by the MTA are collectively referred to as the “Business Combination”). Surviving Pubco, as the successor to Thunder Bridge II following the Business Combination, is referred to herein as the “Company.” This document is both a proxy statement/prospectus containing information about Thunder Bridge II’s extraordinary general meeting and a prospectus of Surviving Pubco with respect to the securities to be issued to Thunder Bridge II’s securityholders and indie’s equityholders in the Business Combination.

In connection with the Domestication, the Business Combination and the other matters described herein, you are cordially invited to attend the extraordinary general meeting (the “Shareholders Meeting”) of Thunder Bridge II to be held at 101 Constitution Ave., NW, Suite 900, Washington, DC 20001, USA at 11:00 a.m. Eastern Time, on June 9, 2021. Only shareholders who held ordinary shares of Thunder Bridge II at the close of business on May 10, 2021 will be entitled to vote at the Shareholders Meeting and at any adjournments thereof.

The Shareholders Meeting will be held at 101 Constitution Ave., NW, Suite 900, Washington, DC 20001, USA and will also be available by way of a virtual meeting conducted via live webcast. You will be able to attend the Shareholders Meeting online, vote and submit your questions during the Shareholders Meeting by visiting https://www.cstproxy.com/thunderbridgeacquisitionii/sm2021. We are pleased to utilize the virtual shareholder meeting technology to (i) provide ready access and cost savings for our shareholders and Thunder Bridge II, and (ii) promote social distancing pursuant to guidance provided by the Center for Disease Control and Prevention and the U.S. Securities and Exchange Commission due to the novel coronavirus. The virtual meeting format allows attendance from any location in the world. The meeting may solely be attended virtually online via the internet.

Thunder Bridge II is a blank check company incorporated on February 13, 2019 as a Cayman Islands exempted company and incorporated for the purpose of effecting a merger, share exchange, asset acquisition, stock purchase, reorganization or similar business combination with one or more businesses. Thunder Bridge II’s units, ordinary shares and warrants are traded on the Nasdaq Stock Market (“Nasdaq”) under the symbols “THBRU,” “THBR” and “THBRW,” respectively. On May 10, 2021 the closing sale prices of Thunder Bridge II’s units, Class A ordinary shares and warrants were $10.99, $10.12 and $1.70, respectively. At the closing of the Business Combination, the units will separate into their component shares of Class A common stock and warrants so that the units will no longer trade separately under “THBRU.” Surviving Pubco has applied for the listing of the Class A common stock and warrants of the Company on Nasdaq following the completion of the Business Combination under the symbols “INDI” and “INDIW,” respectively.

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indie offers highly innovative automotive semiconductors and software solutions for Advanced Driver Assistance Systems (ADAS), including LiDAR, connected car, user experience and electrification applications. These functions represent the core underpinnings of both electric and autonomous vehicles, while the advanced user interfaces are transforming the in-cabin experience to mirror and seamlessly connect to the mobile platforms we rely on every day. indie is an approved vendor to Tier 1 automotive suppliers and its platforms can be found in marquee automotive manufacturers around the world. Headquartered in Aliso Viejo, California, indie has design centers and sales offices in Austin, Texas, Boston, Massachusetts, Detroit, Michigan, San Francisco and San Jose, California, Dresden, Germany, Edinburgh, Scotland, and various locations throughout China. If the proposed Business Combination is not consummated, indie would require additional funding to sustain operations over the next twelve months and execute its business plan. Accordingly, indie’s auditor’s report includes an explanatory paragraph expressing substantial doubt about indie’s ability to continue as a going concern.

At the Shareholders Meeting, Thunder Bridge II’s shareholders will be asked to vote on the following proposals, as more fully described (and defined) in the accompanying proxy statement/prospectus: (i) the Domestication Proposal; (ii) the Merger Proposal; (iii) the Equity Incentive Plan Proposal; (iv) the Director Election Proposal; (v) the Nasdaq Proposal; (vi) the Advisory Charter Proposals; and (vii) the Shareholder Adjournment Proposal, if presented (collectively, the “Shareholder Proposals”).

Thunder Bridge II’s board of directors has unanimously determined that the Shareholder Proposals are advisable, fair to and in the best interests of Thunder Bridge II and its shareholders and unanimously recommends that Thunder Bridge II’s shareholders vote “FOR” each of the Shareholder Proposals to be presented to them.

If the Thunder Bridge II shareholders approve the Merger Proposal and the parties consummate the Business Combination: (i) the holders of Thunder Bridge II Shares (as defined below) issued and outstanding immediately prior to the effective time of the Business Combination (other than any redeemed shares) will receive one share of class A common stock of the Company (“Class A common stock”) in exchange for each Thunder Bridge II Share held by them, (ii) the holders of each whole warrant to purchase Thunder Bridge II Class A ordinary shares will receive one warrant to purchase Class A common stock at an exercise price of $11.50 per share, and (iii) the stakeholders of indie will receive an aggregate of up to approximately 90,000,000 shares of the Company, and up to an additional 10,000,000 shares of Class A common stock issuable upon the achievement of certain stock price performance thresholds of the Company by December 31, 2027, subject to adjustment as more fully described herein. As a result of the Business Combination, indie will become a controlled 72.8% owned subsidiary of the Company.

In connection with the execution of the MTA, Thunder Bridge II entered into the Sponsor Support Agreement, dated December 14, 2020, with the Sponsor (as defined below), pursuant to which, among other thing, the Sponsor agreed to vote its Founder Shares (as defined below) in favor of the Shareholder Proposals.

In connection with the execution of the MTA, certain securityholders of indie entered into a Company Support Agreement, dated December 14, 2020, pursuant to which such securityholders of indie agreed to approve the MTA and the Business Combination.

It is anticipated that, upon completion of the Business Combination, Thunder Bridge II’s Public Shareholders (as defined below) will own approximately 23.3% of the outstanding shares of the Company, the Sponsor will own approximately 5.8% of the outstanding shares of the Company, indie’s existing security holders will own approximately 60.8% of the outstanding shares of the Company (on an as-exchanged basis) and approximately 10.1% of the outstanding shares of the Company will be held by the PIPE Investors. These percentages are calculated based on a number of assumptions and are subject to adjustment in accordance with the terms of the MTA. These relative percentages assume that none of Thunder Bridge II’s existing Public Shareholders exercise their redemption rights in connection with the Business Combination. If any of Thunder Bridge II’s Public Shareholders exercise their redemption rights, or any of the other assumptions underlying these percentages become inaccurate, these percentages may vary from the amounts shown above. Please see “Unaudited Pro Forma Condensed Combined Financial Information” for further information.

Pursuant to Thunder Bridge II’s current Memorandum and Articles of Association, a holder of Public Shares may demand that Thunder Bridge II redeem such shares for cash if the Business Combination is consummated. Holders of Public Shares will be entitled to receive cash for these shares only if, no later than the second business day prior to the date of the Shareholders Meeting, they demand that Thunder Bridge II redeem their shares for cash and deliver their

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shares to Thunder Bridge II’s transfer agent. If the Business Combination is not completed, these shares will not be redeemed. If a holder of Public Shares properly demands redemption, regardless of whether such holder votes for or against the Merger Proposal, Thunder Bridge II will redeem each Public Share for a full pro rata portion of the trust account (as defined in the accompanying proxy statement/prospectus), calculated as of two business days prior to the consummation of the Business Combination. Please see the section titled “Shareholders Meeting — Redemption Rights” for the procedures to be followed if you wish to redeem your public shares for cash.

The obligations of Thunder Bridge II to complete the Business Combination are subject to a number of conditions set forth in the MTA and are summarized in the accompanying proxy statement/prospectus. More information about Thunder Bridge II and indie, the Shareholders Meeting, and the transactions contemplated by the MTA, is contained in the accompanying proxy statement/prospectus. You are encouraged to read the accompanying proxy statement/prospectus in its entirety, including the section entitled “Risk Factors” beginning on page 44.

Your vote is very important. As a condition to the completion of the Business Combination, an affirmative vote of holders of a majority of the voting power of the ordinary shares of Thunder Bridge II entitled to vote on the Shareholder Proposals, who are present and vote at the Shareholders Meeting is required with respect to the Shareholder Proposals (other than (i) the Domestication Proposal, which requires the approval of the holders of at least two-thirds of the voting power of the outstanding ordinary shares entitled to vote on such proposal that are present and vote at the Shareholders Meeting, and (ii) the election of directors pursuant to the Director Election Proposal, which requires each director to be approved by holders of not less than a majority of the Class B ordinary shares of Thunder Bridge II that are present and vote at the Shareholders Meeting).

Thunder Bridge II’s board of directors strongly supports the Business Combination and the other transactions contemplated by the MTA and recommends that you vote in favor of the Shareholder Proposals presented for your approval.

Very truly yours,
/s/ Gary A. Simanson
Gary A. Simanson
President and Chief Executive Officer
Thunder Bridge Acquisition II, Ltd.
, 2021

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued under the accompanying proxy statement/prospectus or determined that the accompanying proxy statement/prospectus is accurate or complete. Any representation to the contrary is a criminal offense.

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ADDITIONAL INFORMATION

The accompanying document is the proxy statement of Thunder Bridge II for the Shareholders Meeting and the prospectus for the securities of Surviving Pubco following the Domestication and the Business Combination. This registration statement and the accompanying proxy statement/prospectus is available without charge to shareholders of Thunder Bridge II upon written or oral request. This document and other filings by Thunder Bridge II with the Securities and Exchange Commission may be obtained by either written or oral request to Gary A. Simanson, Thunder Bridge Acquisition II, Ltd., 9912 Georgetown Pike, Suite D203, Great Falls, Virginia 22066 or by telephone at (202) 431-0507.

The Securities and Exchange Commission maintains an internet site that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the Securities and Exchange Commission. You may obtain copies of the materials described above at the commission’s internet site at www.sec.gov.

In addition, if you have questions about the Shareholder Proposals or the accompanying proxy statement/prospectus, would like additional copies of the accompanying proxy statement/prospectus, or need to obtain proxy cards or other information related to the proxy solicitation, please contact Morrow Sodali LLC, the proxy solicitor for Thunder Bridge II, toll-free at (800) 662-5200 or collect at (203) 658-9400. You will not be charged for any of the documents that you request.

See the section entitled “Where You Can Find More Information” of the accompanying proxy statement/prospectus for further information.

Information contained on the indie website, or any other website, is expressly not incorporated by reference into this proxy statement/prospectus.

To obtain timely delivery of the documents, you must request them no later than five business days before the date of the Shareholders Meeting, or no later than June 2, 2021.

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THUNDER BRIDGE ACQUISITION II, LTD.
9912 Georgetown Pike
Suite D203
Great Falls, Virginia 22066

NOTICE OF EXTRAORDINARY GENERAL MEETING
TO BE HELD ON JUNE 9, 2021.

TO THE SHAREHOLDERS OF THUNDER BRIDGE ACQUISITION II, LTD.:

NOTICE IS HEREBY GIVEN that an extraordinary general meeting (the “Shareholders Meeting”) of Thunder Bridge Acquisition II, Ltd., a Cayman Islands exempted company (“Thunder Bridge II”), will be held at 101 Constitution Ave., NW, Suite 900, Washington, DC 20001, USA, at 11:00 a.m. Eastern Time, on June 9, 2021. You will be able to attend, vote your shares, and submit questions during the Shareholders Meeting via a live webcast available at https://www.cstproxy.com/thunderbridgeacquisitionii/sm2021. The Shareholders Meeting will be held for the sole purpose of considering and voting upon the following proposals:

(1) The Domestication Proposal — To consider and vote upon a proposal by special resolution to change the corporate structure and domicile of Thunder Bridge II by way of continuation from an exempted company incorporated under the laws of the Cayman Islands to a corporation incorporated under the laws of the State of Delaware (the “Domestication”), the replacement of the existing Amended and Restated Memorandum and Articles of Association of Thunder Bridge II with the post-domestication and post-merger Certificate of Incorporation for Surviving Pubco and the change of name of Thunder Bridge II. The Domestication will be effected simultaneously with the Business Combination (as defined below) by Thunder Bridge II filing a Certificate of Corporate Domestication and a Certificate of Incorporation with the Delaware Secretary of State and filing an application to de-register with the Registrar of Companies of the Cayman Islands. Upon the effectiveness of the Domestication, Thunder Bridge II will become a Delaware corporation and will change its corporate name to “Indie Acquisition Company II, Corp.” We refer to this proposal as the “Domestication Proposal.” Simultaneous with the Domestication, a wholly-owned subsidiary of Thunder Bridge II Surviving Pubco, Inc. (“Surviving Pubco”) will merge with and into Thunder Bridge II, with all outstanding securities of Thunder Bridge II being exchanged for corresponding securities in Surviving Pubco, with Surviving Pubco succeeding as successor registrant and public company issuer pursuant to the federal securities laws. As a result of the Domestication and the Business Combination, holders of Thunder Bridge II ordinary shares will receive Class A common stock of Surviving Pubco, and holders of Thunder Bridge II warrants will receive warrants of Surviving Pubco with substantively identical terms. See “Shareholder Proposal 2: The Merger Proposal” for more information. A copy of the post-domestication and post-merger charter for Surviving Pubco is attached hereto as Annex A.

(2) The Merger Proposal — To consider and vote upon a proposal by ordinary resolution to approve the Master Transactions Agreement dated effective as of December 14, 2020 (as amended or supplemented from time to time, the “MTA”) by and among: (a) Surviving Pubco; (b) Thunder Bridge II; (c) TBII Merger Sub Inc., a Delaware corporation and wholly-owned subsidiary of Surviving Pubco (“TBII Merger Sub”); (d) ADK Merger Sub LLC, a Delaware limited liability company and a wholly-owned subsidiary of Surviving Pubco (“ADK Merger Sub”); (e) ADK Service Provider Merger Sub LLC, a Delaware limited liability company and wholly-owned subsidiary of Surviving Pubco (“ADK Service Provider Merger Sub”); (f) ADK Blocker Merger Sub LLC, a Delaware limited liability company and wholly-owned subsidiary of Surviving Pubco (“ADK Blocker Merger Sub,” and collectively with TBII Merger Sub, ADK Merger Sub and ADK Service Provider Merger Sub, the “Merger Subs”); (g) Ay Dee Kay LLC, a California limited liability company (“indie”); (h) the corporate entities listed in the MTA (the “ADK Blocker Group”); (i) ADK Service Provider Holdco, LLC, a Delaware limited liability company (“ADK Service Provider Holdco”); and (j) solely in his capacity as the indie securityholder representative hereunder, Donald McClymont (the “indie Securityholder Representative”), and the transactions contemplated by the MTA, including the issuance of the merger consideration thereunder (collectively, the “Business Combination”). Pursuant to the MTA, among other things, Thunder Bridge II will complete the Domestication, and immediately following the completion of the Domestication, (1) TBII Merger Sub will merge with and into Thunder Bridge II, with all outstanding securities of Thunder Bridge II being exchanged for corresponding securities in Surviving Pubco, and Surviving Pubco succeeding

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as successor registrant and public company issuer pursuant to the federal securities laws and changing its name to indie Semiconductor, Inc., (2) ADK Merger Sub will merge with and into indie, with indie surviving as a controlled 72.8% owned subsidiary of Surviving Pubco, (3) the entities in the ADK Blocker Group will merge with and into ADK Blocker Merger Sub, with ADK Blocker Merger Sub being the surviving limited liability company, and (4) ADK Service Provider Holdco will merge with and into ADK Service Provider Merger Sub ((1) through (4) collectively, the “Mergers”). We refer to this proposal as the “Merger Proposal.” A copy of the MTA is attached to the accompanying proxy statement/prospectus as Annex B.

(3) The Equity Incentive Plan Proposal — To consider and vote upon a proposal by ordinary resolution to approve the 2021 Equity Incentive Plan to be effective after the closing of the Business Combination. We refer to this proposal as the “Equity Incentive Plan Proposal.” A copy of the 2021 Equity Incentive Plan is attached to the accompanying proxy statement/prospectus as Annex C.

(4) The Director Election Proposal — To consider and vote upon a proposal by ordinary resolution to elect nine directors to serve staggered terms on the Company’s board of directors until the 2022, 2023 and 2024 annual meeting of stockholders of the Company, respectively, and until their respective successors are duly elected and qualified. We refer to this proposal as the “Director Election Proposal.”

(5) The Nasdaq Proposal — To consider and vote upon a proposal by ordinary resolution to approve, (i) for purposes of complying with Nasdaq Listing Rules 5635(a) and (b), the issuance of more than 20% of the issued and outstanding Class A common stock and the resulting change in control in connection with the Business Combination, and (ii) for the purposes of complying with Nasdaq Listing Rules 5635(d) the issuance of more than 20% of the issued and outstanding Class A ordinary shares in the PIPE Financing (as defined in the accompanying proxy statement/prospectus), upon the completion of the Business Combination. We refer to this as the “Nasdaq Proposal.”

(6) The Advisory Charter Proposals — to approve and adopt, on a non-binding advisory basis, certain differences between Thunder Bridge II’s current Memorandum and Articles of Association (the “existing charter”) and the proposed charter, which are being presented in accordance with the requirements of the U.S. Securities and Exchange Commission (the “SEC”) as nine separate sub-proposals (which we refer to, collectively, as the “Advisory Charter Proposals”):

(A) Advisory Charter Proposal A — provide that the total number of shares of all classes of capital stock which the Company will have authority to issue is 300,000,000 shares, consisting of (i) 250,000,000 shares of Class A common stock, par value $0.0001 per share, (ii) 40,000,000 shares of Class V common stock, no par value, and (iii) 10,000,000 shares of preferred stock, par value $0.0001 per share.

(B) Advisory Charter Proposal B — provide that special meetings of stockholders of the Company may be called only (i) by the chairman of the board of directors, (ii) by the chief executive officer, or (iii) by the secretary acting at the request of a majority of the total number of directors that the Company would have if there were no vacancies.

(C) Advisory Charter Proposal C — provide that any action of the stockholders of the Company may be taken without a meeting, without prior notice and without a vote, if a consent in writing, setting forth the action so taken, is signed by the holders of outstanding stock having not less than the minimum number of votes that would be necessary to authorize or take such action at a meeting at which all shares entitled to vote thereon were present and voted.

(D) Advisory Charter Proposal D — provide that the Company’s board of directors will be divided into three classes designated as Class I, Class II and Class III.

(E) Advisory Charter Proposal E — provide that directors may be elected by the stockholders only at an annual meeting of stockholders by a plurality of the votes cast.

(F) Advisory Charter Proposal F — provide that any director may be removed from office at any time, but only for cause, by the affirmative vote of the holders of at least 66⅔% of the voting power of the outstanding voting capital stock of the Company, voting together as a single class.

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(G) Advisory Charter Proposal G — provide that the affirmative vote of the holders of at least 66⅔% of the voting power of the outstanding voting capital stock of the Company, voting together as a single class, will be required to amend or repeal, or adopt any provision inconsistent with, provisions relating to calling special meetings of stockholders and stockholder action by written consent. Except as provided in the foregoing, the affirmative vote of the holders of at least a majority in voting power of the outstanding voting capital stock of the Company, voting together as a single class, will be required to amend, alter, change or repeal, or adopt any provision inconsistent with, certain provisions of the Certificate of Incorporation, including provisions relating to limiting liability of and indemnifying directors, amending the Certificate of Incorporation and the forum for certain actions involving the Company.

(H) Advisory Charter Proposal H — provide that the Court of Chancery of the State of Delaware or, if such court does not have subject matter jurisdiction thereof, any federal court located within the State of Delaware, shall be the exclusive forum for certain actions and claims.

(I) Advisory Charter Proposal I — provide that the Company will not be subject to provisions Section 203 of the DGCL, which generally prohibits “interested stockholders” (stockholders holding 15% or more of the outstanding stock) from engaging in business combinations with the Company for a period of time unless certain conditions are met.

(7) The Shareholder Adjournment Proposal — To consider and vote upon a proposal by ordinary resolution to adjourn the Shareholders Meeting to a later date or dates, if necessary to permit further solicitation and vote of proxies if it is determined by Thunder Bridge II that more time is necessary or appropriate to approve one or more proposals at the Shareholders Meeting. We refer to this proposal as the “Shareholder Adjournment Proposal” and, together with the Domestication Proposal, the Merger Proposal, the Equity Incentive Plan Proposal, the Director Election Proposal, and the Nasdaq Proposal as the “Shareholder Proposals.”

The Shareholder Proposals are more fully described in the accompanying proxy statement/prospectus, which we encourage you to read in its entirety before voting. As of May 10, 2021 (the “Record Date”), there were 34,500,000 issued and outstanding Class A ordinary shares of Thunder Bridge II and 8,625,000 issued and outstanding Class B ordinary shares of Thunder Bridge II. Only holders of record of ordinary shares of Thunder Bridge II at the close of business on the Record Date are entitled to notice of the Shareholders Meeting and to vote and have their votes counted at the Shareholders Meeting and any adjournments of the Shareholders Meeting.

After careful consideration, Thunder Bridge II’s board of directors has determined that the Shareholder Proposals are fair to and in the best interests of Thunder Bridge II and its shareholders and unanimously recommends that the holders of Thunder Bridge II’s ordinary shares entitled to vote on the Shareholder Proposals, vote or give instruction to vote “FOR” the Domestication Proposal, “FOR” the Merger Proposal, “FOR” the Equity Incentive Plan Proposal, “FOR” the election of each of the director nominees pursuant to the Director Election Proposal, “FOR” the Nasdaq Proposal and “FOR” the Shareholder Adjournment Proposal, if presented.

The existence of any financial and personal interests of one or more of Thunder Bridge II’s directors may result in a conflict of interest on the part of such director(s) between what he, she or they may believe is in the best interests of Thunder Bridge II and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the Shareholder Proposals. See the section entitled “Shareholder Proposal 2: The Merger Proposal — Interests of Thunder Bridge II’s Directors and Officers and Others in the Business Combination” in the accompanying proxy statement/prospectus for a further discussion of this.

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at least two-thirds of the ordinary shares of Thunder Bridge II as of the Record Date that are present and vote at the Shareholders Meeting. The election of directors pursuant to the Director Election Proposal must be approved by an ordinary resolution of the holders of the Class B ordinary shares of Thunder Bridge II, being the approval of the holders of not less than a majority of such shares as of the Record Date that are present and vote at the Shareholders Meeting.

YOUR VOTE IS VERY IMPORTANT TO US. PLEASE VOTE YOUR SHARES PROMPTLY.

All shareholders of Thunder Bridge II are cordially invited to attend the Shareholders Meeting. To ensure your representation at the Shareholders Meeting, however, you are urged to mark, sign and date the enclosed proxy card and return it as soon as possible in the pre-addressed postage paid envelope provided. If you are a shareholder of record of Thunder Bridge II ordinary shares, you may also cast your vote at the https://www.cstproxy.com/thunderbridgeacquisitionii/sm2021. In light of the novel coronavirus pandemic and to support the well-being of Thunder Bridge II shareholders, the Shareholders Meeting will be utilizing a virtual shareholder meeting format. If you grant a proxy, you may still vote your shares virtually at https://www.cstproxy.com/thunderbridgeacquisitionii/sm2021 if you revoke your proxy before the Shareholders Meeting. If your shares are held in an account at a brokerage firm or bank, or by a nominee, you must instruct your broker, bank or nominee on how to vote your shares or, if you wish to vote at the Shareholders Meeting, obtain a proxy from your broker, bank or nominee. If any of the Domestication Proposal, Merger Proposal, Director Election Proposal, or Nasdaq Proposal fails to receive the required approval by the shareholders of Thunder Bridge II at the Shareholders Meeting, the Business Combination will not be completed.

Whether or not you plan to attend the Shareholders Meeting, we urge you to read the accompanying proxy statement/prospectus (and any documents incorporated into the accompanying proxy statement/prospectus by reference) carefully. Please pay particular attention to the section entitled “Risk Factors” in the accompanying proxy statement/prospectus.

Your vote is important regardless of the number of shares you own. Whether you plan to attend the Shareholders Meeting or not, please mark, sign and date the enclosed proxy card and return it as soon as possible in the envelope provided. If your shares are held in “street name” or are in a margin or similar account, you should contact your broker to ensure that votes related to the shares you beneficially own are properly counted.

Thank you for your participation. We look forward to your continued support.

By Order of the Board of Directors
/s/ Gary A. Simanson
Chief Executive Officer and President
, 2021

IF YOU RETURN YOUR PROXY CARD WITHOUT AN INDICATION OF HOW YOU WISH TO VOTE, YOUR SHARES WILL BE VOTED IN FAVOR OF EACH OF THE SHAREHOLDER PROPOSALS. YOU MAY EXERCISE YOUR RIGHTS TO DEMAND THAT THUNDER BRIDGE II REDEEM YOUR SHARES FOR A PRO RATA PORTION OF THE FUNDS HELD IN THE TRUST ACCOUNT WHETHER YOU VOTE FOR OR AGAINST THE SHAREHOLDER PROPOSALS. TO EXERCISE YOUR REDEMPTION RIGHTS, YOU MUST TENDER YOUR SHARES TO THUNDER BRIDGE II’S TRANSFER AGENT AT LEAST TWO (2) BUSINESS DAYS PRIOR TO THE SHAREHOLDERS MEETING. YOU MAY TENDER YOUR SHARES FOR REDEMPTION BY EITHER DELIVERING YOUR SHARE CERTIFICATE TO THE TRANSFER AGENT OR BY DELIVERING YOUR SHARES ELECTRONICALLY USING THE DEPOSITORY TRUST COMPANY’S DEPOSIT/WITHDRAWAL AT CUSTODIAN (“DWAC”) SYSTEM. IF THE BUSINESS COMBINATION IS NOT COMPLETED, THEN THESE TENDERED SHARES WILL NOT BE REDEEMED FOR CASH AND WILL BE RETURNED TO THE APPLICABLE SHAREHOLDER. IF YOU HOLD THE SHARES IN STREET NAME, YOU WILL NEED TO INSTRUCT THE ACCOUNT EXECUTIVE AT YOUR BROKER OR BANK TO WITHDRAW THE SHARES FROM YOUR ACCOUNT IN ORDER TO EXERCISE YOUR REDEMPTION RIGHTS. SEE THE SECTION ENTITLED “SHAREHOLDERS MEETING — REDEMPTION RIGHTS” FOR MORE SPECIFIC INSTRUCTIONS.

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TABLE OF CONTENTS

		Page
FREQUENTLY USED TERMS		1
CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS		6
SUMMARY OF THE PROXY STATEMENT/PROSPECTUS		8
QUESTIONS AND ANSWERS		23
SELECTED HISTORICAL FINANCIAL DATA OF THUNDER BRIDGE II		38
SELECTED HISTORICAL CONSOLIDATED FINANCIAL AND OTHER DATA OF INDIE		39
SELECTED UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL DATA		41
COMPARATIVE PER SHARE INFORMATION		43
RISK FACTORS		44
SHAREHOLDERS MEETING		75
SHAREHOLDER PROPOSAL 1: THE DOMESTICATION PROPOSAL		80
SHAREHOLDER PROPOSAL 2: THE MERGER PROPOSAL		90
SHAREHOLDER PROPOSAL 3: THE EQUITY INCENTIVE PLAN PROPOSAL		133
SHAREHOLDER PROPOSAL 4: THE DIRECTOR ELECTION PROPOSAL		138
SHAREHOLDER PROPOSAL 5: THE NASDAQ PROPOSAL		144
SHAREHOLDER PROPOSAL 6: THE ADVISORY CHARTER PROPOSALS		146
SHAREHOLDER PROPOSAL 7: THE SHAREHOLDER ADJOURNMENT PROPOSAL		150
UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION		151
INFORMATION ABOUT THUNDER BRIDGE II		160
DIRECTORS, OFFICERS, EXECUTIVE COMPENSATION AND CORPORATE GOVERNANCE OF THUNDER BRIDGE II PRIOR TO THE BUSINESS COMBINATION		164
MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS OF THUNDER BRIDGE II		172
DESCRIPTION OF THUNDER BRIDGE II’S AND THE COMPANY’S SECURITIES		177
MARKET PRICE AND DIVIDENDS OF SECURITIES		188
BENEFICIAL OWNERSHIP OF SECURITIES		190
CERTAIN RELATIONSHIPS AND RELATED PERSON TRANSACTIONS		193
INFORMATION ABOUT INDIE		195
MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS OF INDIE		203
MANAGEMENT OF INDIE		213
EXECUTIVE COMPENSATION OF INDIE		215
MANAGEMENT OF THE COMPANY FOLLOWING THE BUSINESS COMBINATION		217
SECURITIES ACT RESTRICTIONS ON RESALE OF THE COMPANY’S SECURITIES		222
APPRAISAL RIGHTS		223
OTHER SHAREHOLDER COMMUNICATIONS		223
LEGAL MATTERS		223
EXPERTS		223
DELIVERY OF DOCUMENTS TO SHAREHOLDERS		223
TRANSFER AGENT AND REGISTRAR		223
SUBMISSION OF SHAREHOLDER PROPOSALS		224
FUTURE STOCKHOLDER PROPOSALS		224
WHERE YOU CAN FIND MORE INFORMATION		224
INDEX TO FINANCIAL STATEMENTS		F-1

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		Page
ANNEXES
ANNEX A Certificate of Incorporation of indie Semiconductor, Inc.		A-1
ANNEX B-1 Master Transactions Agreement, as amended		B-1-1
ANNEX B-2 Amendment to Master Transactions Agreement		B-2-1
ANNEX C 2021 Equity Incentive Plan		C-1
ANNEX D Form of Exchange Agreement		D-1
ANNEX E Form of Tax Receivable Agreement		E-1
ANNEX F Company Support Agreement		F-1
ANNEX G Sponsor Support Agreement		G-1
ANNEX H Sponsor Letter Agreement		H-1

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FREQUENTLY USED TERMS

Definitions

Unless otherwise stated or unless the context otherwise requires, the terms “we,” “us,” “our,” and “Thunder Bridge II” refer to Thunder Bridge Acquisition II, Ltd. (which prior to the Domestication is an exempted company incorporated under the laws of the Cayman Islands and thereafter a corporation incorporated under the laws of the State of Delaware).

In this document:

“2021 Equity Incentive Plan” means the indie Semiconductor, Inc. 2021 Omnibus Equity Incentive Plan, which will become effective following the Business Combination. A copy of the 2021 Equity Incentive Plan is attached to this proxy statement/prospectus as Annex C.

“Adjournment Proposal” means the proposal by ordinary resolution to be considered at the Shareholders Meeting to adjourn the Shareholders Meeting to a later date or dates, if necessary to permit further solicitation and vote of proxies if it is determined by Thunder Bridge II that more time is necessary or appropriate to approve one or more proposal at the Shareholders Meeting.

“ADK Principal Owners” means Donald McClymont, Ichiro Aoki, Scott Kee, David Kang and Bison Capital Partners IV, L.P.

“Advisory Charter Proposals” means the proposals by non-binding ordinary resolution to approve certain governance provisions contained in the proposed charter.

“Amended Operating Agreement” means the Eighth Amended and Restated Operating Agreement of indie to be in place upon the completion of the Business Combination. A copy of the Amended Operating Agreement is incorporated by reference as an exhibit to the registration statement of which this proxy statement/prospectus is a part.

“Business Combination” means the transactions contemplated by the MTA.

“Bylaws” mean the proposed bylaws of the Company to be in effect as of the Closing of the Business Combination, a form of which is attached as an exhibit to the registration statement of which this proxy statement/prospectus forms a part.

“Certificate of Incorporation” means the proposed amended and restated certificate of incorporation of the Company to be in effect following the Domestication and the Business Combination. A copy of the Certificate of Incorporation is attached to this proxy statement/prospectus as Annex A

“Class A common stock” means the Class A common stock of the Company, par value $0.0001 per share.

“Class A ordinary shares” means the Class A ordinary shares of Thunder Bridge II, par value $0.0001 per share.

“Class B ordinary shares” means the Class B ordinary shares of Thunder Bridge II, par value $0.0001 per share.

“Class V common stock” means the Class V common stock of the Company, no par value.

“Closing” means the closing of the Business Combination.

“Code” means the Internal Revenue Code of 1986, as amended.

“Companies Act” refers to the Cayman Islands Companies Act (As Revised).

“Company” means Surviving Pubco, as a Delaware corporation by way of continuation following the Domestication and the Business Combination. Coincident with the Domestication and simultaneously with the Business Combination, Surviving Pubco will change its corporate name to “indie Semiconductor, Inc.” and will be the successor registrant and public company to Thunder Bridge II pursuant to the federal securities laws.

“Company Board” means the board of directors of the Company subsequent to the completion of the Business Combination.

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“Company Shares” means, collectively, all shares of the Class A common stock and Class V common stock of the Company.

“CRULLCA” means the California Revised Uniform Limited Liability Company Act, as amended.

“DGCL” means the Delaware General Corporation Law, as amended.

“DLLCA” means the Delaware Limited Liability Company Act, as amended.

“Director Election Proposal” means the proposal by ordinary resolution to be considered at the Shareholders Meeting to elect nine directors to serve staggered terms on the Company Board until the 2022, 2023 and 2024 annual meeting of stockholders, respectively and until their respective successors are duly elected and qualified.

“Domestication” means the continuation of Thunder Bridge II by way of domestication of Thunder Bridge II into a Delaware corporation, with the ordinary shares of Thunder Bridge II becoming shares of Class A common stock of the Delaware corporation under the applicable provisions of the Companies Act and the DGCL; the term includes all matters and necessary or ancillary changes in order to effect such Domestication, including the adoption of the Certificate of Incorporation for the Company (as attached hereto at Annex A) consistent with the DGCL and changing the name and registered office of Thunder Bridge II.

“Domestication Proposal” means the proposal by special resolution to be considered at the Shareholders Meeting to approve the Domestication.

“DWAC” means The Depository Trust Company’s deposit/withdrawal at custodian system.

“Equity Incentive Plan Proposal” means the proposal by ordinary resolution to be considered at the Shareholders Meeting to approve the 2021 Equity Incentive Plan of the Company.

“Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended.

“Exchange Agreement” means the Exchange Agreement to be entered into among the Company, indie and certain indie Equity Holders upon the completion of the Business Combination, a form of which is attached as an exhibit to the registration statement of which this proxy statement/prospectus forms a part.

“Founder Shares” means the 8,625,000 currently outstanding Class B ordinary shares of Thunder Bridge II owned by the Sponsor.

“GAAP” means U.S. generally accepted accounting principles.

“indie” means Ay Dee Kay, LLC, a California limited liability company.

“indie Equity Holder” means a member of indie prior to the Closing of the Business Combination.

“indie Securityholder Representative” means Donald McClymont, acting in his capacity as the representative of the securityholders of indie as set forth in the MTA.

“Insider Letter Agreement” means Thunder Bridge II’s letter agreement with its Sponsor, directors and officers, dated August 8, 2019, containing provisions relating to transfer restrictions of the Founder Shares and Private Placement Warrants, indemnification of the Trust Account, waiver of Redemption Rights and participation in liquidation distributions from the Trust Account.

“IPO” means Thunder Bridge II’s initial public offering of its units, consisting of Class A ordinary shares and warrants, pursuant to a registration statement on Form S-1 declared effective by the SEC on August 8, 2019 (SEC File No. 333-232688). On August 13, 2019, Thunder Bridge II completed its initial public offering.

“Memorandum and Articles of Association” means Thunder Bridge II’s current amended and restated Memorandum and Articles of Association, as may hereafter be amended.

“Mergers” means the following statutory mergers pursuant to the terms of the MTA and under the applicable provisions of the DGCL, DLLCA, and the CRULLCA, (1) the TBII Merger Sub merger with and into Thunder Bridge II, with all outstanding securities of Thunder Bridge II being exchanged for corresponding securities in Surviving Pubco, and Surviving Pubco succeeding as successor registrant and public company issuer pursuant to the federal

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securities laws and changing its name to indie Semiconductor, Inc., (2) the ADK Merger Sub merger with and into indie, with indie surviving as a controlled 72.8% owned subsidiary of Surviving Pubco, (3) the merger of the entities in the ADK Blocker Group with and into ADK Blocker Merger Sub, with ADK Blocker Merger Sub being the surviving limited liability company, and (4) the ADK Service Provider Holdco merger with and into ADK Service Provider Merger Sub, with ADK Service Provider Merger Sub being the surviving limited liability company.

“Merger Proposal” means the proposal by ordinary resolution to be considered at the Shareholders Meeting to approve the Business Combination.

“Merger Subs” means TBII Merger Sub, ADK Merger Sub, ADK Blocker Merger Sub and ADK Service Provider Merger Sub.

“MTA” means the Master Transactions Agreement, dated effective as of December 14, 2020 by and among Surviving Pubco, Thunder Bridge II, the Merger Subs, indie, ADK Blocker Group, ADK Service Provider Holdco and, solely in his capacity as the indie Securityholder Representative thereunder, Donald McClymont, as it may be amended and supplemented from time to time. A copy of the MTA is attached to this proxy statement/prospectus as Annex B-1 and a copy of the Amendment to the Master Transactions Agreement, dated effective May 3, 2021, is attached to this proxy statement/prospectus as Annex B-2.

“Nasdaq” means The Nasdaq Stock Market, LLC.

“Nasdaq Proposal” means the proposal by ordinary resolution to be considered at the Shareholders Meeting to approve, (i) for purposes of complying with Nasdaq Listing Rules 5635(a) and (b), the issuance of more than 20% of the issued and outstanding Class A common stock and the resulting change in control in connection with the Business Combination, and (ii) for the purposes of complying with Nasdaq Listing Rules 5635(d) the issuance of more than 20% of the issued and outstanding Class A ordinary shares in the PIPE Financing (as defined in the accompanying proxy statement/prospectus), upon the completion of the Business Combination.

“Phantom Equity Plan” means indie’s Phantom Equity Plan pursuant to the terms of such plan and award agreements, certain employees and consultants of indie may be issued Phantom Equity Units, which upon vesting, will entitle the holder to receive shares of Class A common stock or, at the discretion of Surviving Pubco, cash equivalent to the fair market value of a specified number of shares of Class A common stock.

“Phantom Equity Units” means units issued under the Phantom Equity Plan.

“PIPE Financing” means the expected issuance and sale of $150 million of Thunder Bridge II’s Class A ordinary shares in a private placement to the PIPE Investors pursuant to the Subscription Agreements.

“PIPE Investors” means the accredited investors and qualified institutional buyers who entered into the Subscription Agreements with Thunder Bridge II for the PIPE Financing.

“Post-Merger indie Units” means units representing limited liability company interests of indie as the surviving company following the merger of ADK Merger Sub with and into indie.

“Private Placement Warrants” means the 8,650,000 private placement warrants, each exercisable for one Class A ordinary share of Thunder Bridge II at $11.50 per share, purchased by the Sponsor for a purchase price of $8,650,000, or $1.00 per warrant.

“Public Shareholders” means the holders of Thunder Bridge II Class A ordinary shares (whether such shares were purchased in the IPO or thereafter in the open market).

“Public Shares” means the 34,500,000 Thunder Bridge II Class A ordinary shares (whether such shares were purchased in the IPO or thereafter in the open market).

“Public Warrants” means the 17,250,000 Thunder Bridge II warrants (whether such warrants were purchased in the IPO or thereafter in the open market).

“Public Warrant Holders” means the holders of the Public Warrants.

“Record Date” means May 10, 2021.

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“Redemption” means the redemption of Public Shares for the Redemption Price.

“Redemption Price” means an amount equal to a pro rata portion of the aggregate amount then on deposit in the Trust Account in accordance with the Memorandum and Articles of Association (as equitably adjusted for share subdivisions, share dividends, combinations, recapitalizations and the like after the Closing). The Redemption Price will be calculated two days prior to the completion of the Business Combination in accordance with Thunder Bridge II’s Memorandum and Articles of Association, as currently in effect.

“Redemption Rights” means the rights of the Thunder Bridge II Public Shareholders to demand Redemption of their Public Shares for cash in accordance with the procedures set forth in the Memorandum and Articles of Association and this proxy statement/prospectus.

“Sarbanes-Oxley Act” means the Sarbanes-Oxley Act of 2002.

“SEC” means the United States Securities and Exchange Commission.

“Shareholder Proposals” means, collectively, (i) the Domestication Proposal, (ii) the Merger Proposal, (iii) the Equity Incentive Plan Proposal, (iv) the Director Election Proposal, (v) the Nasdaq Proposal, (vi) the Advisory Charter Proposal, and (vii) the Shareholder Adjournment Proposal, if presented.

“Shareholders Meeting” means the extraordinary general meeting of Thunder Bridge II, to be held at 101 Constitution Ave., NW, Suite 900, Washington, DC 20001, USA and utilizing a virtual shareholder meeting format at 11:00 a.m. Eastern Time on June 9, 2021, and any adjournments thereof.

“Securities Act” means the Securities Act of 1933, as amended.

“Sponsor” means Thunder Bridge Acquisition II LLC, a Delaware limited liability company.

“Sponsor Letter Agreement” means that certain Sponsor Earnout Letter, dated December 14, 2020, by and among Sponsor, Thunder Bridge II and indie.

“Subscription Agreements” means the Subscription Agreements, each dated December 14, 2020, entered into between Thunder Bridge II and each of the PIPE Investors for the PIPE Financing.

“Surviving Pubco” means, prior to the Business Combination, Thunder Bridge II Surviving Pubco, Inc., and after giving effect to the Business Combination, indie Semiconductor, Inc., the successor registrant to Thunder Bridge II for the purposes of the federal securities laws.

“Target Companies” means indie and its subsidiaries.

“Tax Receivable Agreement” means the Tax Receivable Agreement to be entered into between the Company and certain indie Equity Holders upon the completion of the Business Combination, a form of which is incorporated by reference as an exhibit to the registration statement of which this proxy statement/prospectus forms a part.

“Thunder Bridge II” means Thunder Bridge Acquisition II, Ltd.

“Thunder Bridge II Board” means the board of directors of Thunder Bridge II.

“Thunder Bridge II Shares” means, collectively, the Class A ordinary shares and the Class B ordinary shares of Thunder Bridge II.

“Transfer Agent” means Continental Stock Transfer & Trust Company.

“Trust Account” means the trust account of Thunder Bridge II, which holds the net proceeds from the IPO and the sale of the Private Placement Warrants, together with interest earned thereon, less amounts released to pay taxes.

“Units” means the units sold in the IPO (including pursuant to the overallotment option), each consisting of a Class A ordinary share of Thunder Bridge II and one half of one Warrant.

“Warrants” means the Private Placement Warrants and the Public Warrants.

“Warrant Agreement” means the Warrant Agreement, dated August 8, 2019, between Thunder Bridge II and the Transfer Agent, which governs Thunder Bridge II’s outstanding Warrants.

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Share Calculations and Ownership Percentages

Unless otherwise specified (including in the sections entitled “Unaudited Pro Forma Condensed Combined Financial Information” and “Beneficial Ownership of Securities”), the share calculations and ownership percentages set forth in this proxy statement/prospectus with respect to the Company’s stockholders following the Business Combination are for illustrative purposes only and assume the following (certain capitalized terms below are defined elsewhere in this proxy statement/prospectus):

1. No Public Shareholders exercise their Redemption Rights in connection with the Closing of the Business Combination, and the balance of the Trust Account as of the Closing is the same as its balance on December 31, 2020 of $349.6 million. Please see the section entitled “Shareholders Meeting — Redemption Rights.”

2. No Thunder Bridge II warrant holders exercise any of the 17,250,000 Public Warrants or the 8,650,000 Private Placement Warrants that will remain outstanding following the Business Combination.

3. All Post-Merger indie Units and Phantom Equity Units are exchanged for Class A common stock at such time (even if not yet permitted under the terms of the Exchange Agreement or vested, as applicable). The exact number of Post-Merger indie Units actually exchanged at the Closing will depend upon the election of the holders of such securities prior to the Closing. The Phantom Equity Units will not be exchanged for Class A common stock until six months after the Closing. Please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Exchange Agreement.”

4. All warrants to purchase indie units will be exercised in full for cash immediately prior to the Closing of the Business Combination.

5. The 3.45 million shares of Class A common stock to be held in escrow in accordance with the Sponsor Letter Agreement are treated as if owned by the Sponsor, although they will be held in escrow and subject to return and cancellation by the Company if the stock price performance thresholds are not met as further described in the Sponsor Letter Agreement. Please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Sponsor Letter Agreement.”

6. No Earn-Out Shares are issued. Please see the section entitled “Shareholder Proposal 2: The Merger Proposal — The MTA — The Earn-Out.”

7. The PIPE Financing is consummated in accordance with its terms for $150 million, with Thunder Bridge II issuing 15 million shares of Class A ordinary shares to the PIPE Investors. Please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Subscription Agreements; Lock-up Agreements.”

8. Assumes no Closing Adjustment (in other words, the expected indebtedness of the Target Companies as of the Closing does not exceed the amount of cash and cash equivalents of the Target Companies immediately prior to the Effective Time). Please see the section entitled “Shareholder Proposal 2: The Merger Proposal — The MTA — Merger Consideration.”

9. Other than the PIPE Financing, there are (a) no other issuances of equity securities of Thunder Bridge II prior to or in connection with the Closing, and (b) no issuance of any equity awards that may be issued under the proposed 2021 Equity Incentive Plan following the Business Combination, which may include the 3,013,391 shares of Class A restricted stock units currently expected to be issued to certain employees and directors of indie or that may be issued to directors of the Company after the Closing as described under the section entitled “Shareholder Proposal 3: The Equity Incentive Plan Proposal” and the section entitled “Executive Compensation of indie — Key Compensation Actions in 2021 — Equity Grants.”

Market and Industry Data

Information contained in this proxy statement/prospectus concerning the market and the industry in which indie competes, including its market position, general expectations of market opportunity and market size, is based on information from various third-party sources, on assumptions made by indie based on such sources and indie’s knowledge of the markets for its services and solutions. Any estimates provided herein involve numerous assumptions and limitations, and you are cautioned not to give undue weight to such information. The industry in which indie operates is subject to a high degree of uncertainty and risk. As a result, the estimates and market and industry information provided in this proxy statement/prospectus are subject to change based on various factors, including those described in the section entitled “Risk Factors — Risks Related to indie’s Business” and elsewhere in this proxy statement/prospectus.

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CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement/prospectus contains forward-looking statements. These forward-looking statements relate to expectations for future financial performance, business strategies or expectations for our business and indie’s business, and the timing and ability for Thunder Bridge II and indie to complete the Business Combination. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. Forward-looking statements are typically identified by words such as “plan,” “believe,” “expect,” “anticipate,” “intend,” “outlook,” “estimate,” “forecast,” “project,” “continue,” “could,” “may,” “might,” “possible,” “potential,” “predict,” “should,” “would” and other similar words and expressions, but the absence of these words does not mean that a statement is not forward-looking.

These forward-looking statements are based on information available as of the date of this proxy statement/prospectus and Thunder Bridge II and indie managements’ current expectations, forecasts and assumptions, and involve a number of judgments, known and unknown risks and uncertainties and other factors, many of which are outside the control of Thunder Bridge II, indie and their respective directors, officers and affiliates. Accordingly, forward-looking statements should not be relied upon as representing Thunder Bridge II’s views as of any subsequent date. Thunder Bridge II does not undertake any obligation to update, add or to otherwise correct any forward-looking statements contained herein to reflect events or circumstances after the date they were made, whether as a result of new information, future events, inaccuracies that become apparent after the date hereof or otherwise, except as may be required under applicable securities laws.

You should not place undue reliance on these forward-looking statements in deciding how your vote should be cast or in voting your shares on the Shareholder Proposals. As a result of a number of known and unknown risks and uncertainties, actual results or performance may be materially different from those expressed or implied by these forward-looking statements. These risks and uncertainties include, but are not limited to, those factors described in “Risk Factors,” those discussed and identified in public filings made with the SEC by Thunder Bridge II and Surviving Pubco and the following:

• indie’s future capital requirements and sources and uses of cash;

• indie’s ability to obtain funding for its operations and future growth;

• changes in the market for indie’s products and services;

• expansion plans and opportunities;

• the above-average industry growth of product and market areas that indie has targeted;

• indie’s plan to increase revenue through the introduction of new products within its existing product families as well as in new product categories and families;

• the cyclical nature of the semiconductor industry;

• indie’s ability to successfully introduce new technologies and products;

• the demand for the goods into which indie’s products are incorporated;

• indie’s ability to accurately estimate demand and obtain supplies from third-party producers;

• indie’s ability to win competitive bid selection processes;

• the occurrence of any event, change or other circumstances that could delay the Business Combination or give rise to the termination of the MTA;

• the outcome of any legal proceedings that may be instituted against indie or Thunder Bridge II following announcement of the proposed Business Combination and transactions contemplated thereby;

• the inability to complete the Business Combination due to the failure to obtain approval of the Thunder Bridge II shareholders, the inability to complete the PIPE Financing, the failure of Thunder Bridge II to retain sufficient cash in the Trust Account or find replacement cash to meet the requirements of the MTA or the failure to meet other conditions to closing in the MTA;

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• the inability to maintain the listing of the Class A common stock of the Company on Nasdaq following the Business Combination;

• the risk that the proposed Business Combination disrupts current plans and operations;

• the ability to recognize the anticipated benefits of the Business Combination, which may be affected by, among other things, competition, and the ability of the Company to grow and manage growth profitably;

• costs related to the Business Combination; and

• other risks and uncertainties indicated in this proxy statement/prospectus, including those set forth under the section entitled “Risk Factors.”

Should one or more of these risks or uncertainties materialize or should any of the assumptions made by the management of Thunder Bridge II and indie prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements.

All subsequent written and oral forward-looking statements concerning the Business Combination or other matters addressed in this proxy statement/prospectus and attributable to Thunder Bridge II, indie or any person acting on their behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this proxy statement/prospectus. Except to the extent required by applicable law or regulation, Thunder Bridge II and indie undertake no obligation to update these forward-looking statements to reflect events or circumstances after the date of this proxy statement/prospectus or to reflect the occurrence of unanticipated events.

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SUMMARY OF THE PROXY STATEMENT/PROSPECTUS

This summary highlights selected information from this proxy statement/prospectus, but does not contain all of the information that may be important to you. To better understand the Shareholder Proposals to be considered at the Shareholders Meeting, including the Merger Proposal, whether or not you plan to attend such meeting, we urge you to read this proxy statement/prospectus (including the annexes) carefully, including the section entitled “Risk Factors” beginning on page 44. See also the section entitled “Where You Can Find More Information.”

Parties to the Business Combination

Thunder Bridge II

Thunder Bridge II was incorporated as a Cayman Islands exempted company on February 13, 2019 as a blank check company whose sole purpose is to acquire, through a merger, share exchange, asset acquisition, share purchase, reorganization or similar business combination, one or more businesses or entities. On February 19, 2019, the Founder Shares (an aggregate of 8,625,000 Class B ordinary shares) were sold to the Sponsor at a price of approximately $0.003 per share, for an aggregate price of $25,000. Such shares had an aggregate market value of approximately $87.3 million based on the last sale price of $10.12 per share on Nasdaq on May 10, 2021.

On August 8, 2019, Thunder Bridge II completed its IPO of 34,500,000 units. Each unit consists of one Class A ordinary share and one-half of a redeemable warrant, with each whole warrant entitling the holder thereof to purchase one Class A ordinary share for $11.50 per share. The units were sold at a price of $10.00 per Unit, generating gross proceeds to Thunder Bridge II of $345,000,000. As a result of the underwriters exercising the over-allotment in full, no Founder Shares were forfeited. In addition, Thunder Bridge II completed the sale of the Private Placement Warrants (8,650,000 warrants at a price of $1.00 per warrant) in a private placement to the Sponsor, generating gross proceeds of $8,650,000. Such warrants had an aggregate market value of approximately $14.7 million based on the last sale price of $1.70 per warrant on Nasdaq on May 10, 2021. A total of $345,000,000 of the net proceeds from the IPO and the Private Placement Warrants were deposited in the Trust Account established for the benefit of the Public Shareholders and the remaining proceeds became available to be used to provide for business, legal and accounting due diligence on prospective business combinations and continuing general and administrative expenses. The net proceeds deposited into the Trust Account remain on deposit in the Trust Account earning interest except those certain amounts withdrawn in order to pay tax obligations. As of December 31, 2020, there was approximately $349.6 million held in the Trust Account. Thunder Bridge II estimates that it has incurred approximately $570,000 in expenses directly attributable to due diligence and negotiating expenses in connection with the Business Combination, which was or will be borne by Thunder Bridge II and not its Sponsor, officers or directors.

Thunder Bridge II’s principal executive offices are located at 9912 Georgetown Pike, Suite D203, Great Falls, Virginia 22066 and its phone number is (202) 431-0507.

Surviving Pubco

Surviving Pubco is a Delaware corporation formed on December 4, 2020 for the purpose of facilitating the Business Combinations. As a result of the Domestication and Mergers, Surviving Pubco will succeed to Thunder Bridge II as registrant and public company pursuant to the federal securities laws, and will change its name to indie Semiconductor, Inc. Prior to the Business Combination, Surviving Pubco has had no business activity or operations other than in preparation for the Business Combination.

Surviving Pubco’s principal executive offices are located at 9912 Georgetown Pike, Suite D203, Great Falls, Virginia 22066 and its phone number is (202) 431-0507.

Merger Subs

TBII Merger Sub is a Delaware corporation and wholly-owned subsidiary of Surviving Pubco. Each of ADK Merger Sub, ADK Blocker Merger Sub, and ADK Service Provider Merger Sub is a Delaware limited liability company and wholly-owned subsidiary of Surviving Pubco formed on December 4, 2020. In the Mergers, TBII Merger Sub will merge with and into Thunder Bridge II, ADK Blocker Group will merge with and into ADK Merger Sub, ADK Service Provider Holdco will merge with and into ADK Service Provider Merger Sub, and ADK Merger Sub will merge with and into indie with indie being the surviving entity and becoming a 72.8% owned subsidiary of the Company. Prior to the Business Combination, no Merger Sub has had any business activity or operations other than in preparation for the Business Combination.

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Each Merger Sub’s principal executive offices are located at 9912 Georgetown Pike, Suite D203, Great Falls, Virginia 22066 and its phone number is (202) 431-0507.

indie

indie’s principal executive offices are located at 32 Journey, Aliso Viejo, California 92656 and its phone number is (949) 608-0854.

The Proposals to be Submitted at the Shareholders Meeting

Shareholder Proposal 1: The Domestication Proposal

Thunder Bridge II is proposing to change its corporate structure and domicile by way of continuation from an exempted company incorporated under the laws of the Cayman Islands to a corporation incorporated under the laws of the State of Delaware. The Domestication will become effective simultaneously with the completion of the Business Combination and will be effected by the filing of a Certificate of Corporate Domestication and a Certificate of Incorporation with the Delaware Secretary of State and the filing of an application to de-register with the Registrar of Companies of the Cayman Islands and all outstanding securities of Thunder Bridge II will convert to outstanding securities of the continuing Delaware corporation, as described in more detail in this proxy statement/prospectus. As a result of the Domestication and Business Combination, former holders of securities of Thunder Bridge II will hold corresponding securities in Surviving Pubco, with Surviving Pubco succeeding as successor registrant and public company issuer to Thunder Bridge II pursuant to the federal securities laws and changing its name to indie Semiconductor, Inc. Please read the section entitled “Shareholder Proposal 1: The Domestication Proposal.”

Shareholder Proposal 2: The Merger Proposal

Thunder Bridge II and indie have agreed to the Business Combination under the terms the MTA. Pursuant to the terms set forth in the MTA, and subject to the satisfaction or waiver of the conditions to the Closing therein, immediately following the completion of the Domestication, (1) TBII Merger Sub will merge with and into Thunder Bridge II, with all outstanding securities of Thunder Bridge II being exchanged for corresponding securities in Surviving Pubco, and Surviving Pubco succeeding as successor registrant and public company issuer pursuant to the federal securities laws and changing its name to indie Semiconductor, Inc., (2) ADK Merger Sub will merge with and into indie, with indie surviving as a controlled 72.8% owned subsidiary of Surviving Pubco, (3) the entities in the ADK Blocker Group will merge with and into ADK Blocker Merger Sub, with ADK Blocker Merger Sub being the surviving limited liability company, and (4) ADK Service Provider Holdco will merge with and into ADK Service Provider Merger Sub, with ADK Service Provider Holdco being the surviving limited liability company.

Master Transactions Agreement

In connection with the completion of the Mergers, the indie Equity Holders will collectively receive as consideration for their existing limited liability company interests of indie:

(i) a number of shares of Class A common stock of the Company or Post-Merger indie Units (in each case calculated based on a value of $10.00 per security) equal or exchangeable, as the case may be, for up to 90,000,000 shares of Class A common stock of the Company less the Class A common stock reserved for future issuance upon the vesting of the Phantom Equity Units, valued at $10.00 per share, as may be adjusted downward by an amount equal to the amount that indebtedness of the Target Companies exceeds the amount of cash held by the Target Companies at the Closing; the Post-Merger indie Units will be exchangeable from

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time to time at the option of the holder for shares of Class A common stock on a one-for-one basis (subject to customary conversion rate adjustments, including for stock splits, stock dividends and reclassifications and other terms of the Exchange Agreement); and

(ii) the contingent right to receive a number of shares of Class A common stock of the Company or Post-Merger indie Units equal to, or exchangeable for, up to 10,000,000 shares of Class A common stock of the Company, less shares of Class A common stock reserved for possible issuance to the holders of Phantom Equity Units, subject to the satisfaction of certain stock-price based performance thresholds (such Class A common stock of Post-Merger indie Units, as the case may be are collectively referred to as the “Earn-Out Shares”).

Additionally, immediately following the completion of the Mergers, (i) the Company will issue to indie 34,021,833 shares of Class V common stock of the Company and (ii) indie will distribute the number of shares of Class V common stock to the ADK Principal Holders equal to the number of Post-Merger indie Units held by such holder (the “Class V Holders”). The Class V common stock provides no economic rights in the Company to the holder thereof; however, each Class V Holder will be entitled to vote with the holders of Class A common stock of the Company, with each Class V share entitling the holder to per each Class V share at the time of such vote (subject to customary conversion rate adjustments for stock splits, stock dividends and reclassifications).

The obligations of the parties to the MTA to effect the Closing are subject to a number of closing conditions, including, among others:

With respect to the obligations of all of the parties to the MTA:

• termination or expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”),

• approval by Thunder Bridge II’s shareholders of the Domestication Proposal, the Merger Proposal, the Director Election Proposal and the Nasdaq Proposal,

• approval by the indie Equity Holders of the Business Combination,

• the contribution of certain holders of Class B Units of indie of their Class B Units to ADK Service Provider Holdco, in exchange for interests in ADK Service Provider Holdco, which contribution has already occurred,

• the effectiveness of the registration statement (of which this proxy statement/prospectus forms a part), and

• immediately prior to the Closing, after giving effect to the completion of the Redemptions, Thunder Bridge II, without regard to any assets or liabilities of the Target Companies, having net tangible assets of at least $5,000,001.

With respect to the obligations of indie, among others:

• the accuracy of representations, warranties and covenants,

• Thunder Bridge II having delivered the Merger Consideration (as defined below),

• after giving effect to the completion of the Closing, the Company having no indebtedness,

• upon the completion of the Closing, no person or group (excluding any indie Equity Holder, the Sponsor or any PIPE Investor) owning in excess of 9.9% of the issued and outstanding shares of Company Shares, and no three persons or groups (excluding any indie Equity Holder, the Sponsor or any PIPE Investor) owning in the aggregate in excess of 25% of the issued and outstanding Company Shares,

• the Class A common stock (including the shares of Class A common stock issuable in connection with the Domestication and upon exchange of Post-Merger indie Units) having been listed on Nasdaq and being eligible for continued listing on Nasdaq following the Closing and after giving effect to the Redemptions (as if it were a new initial listing by an issuer that had never been listed prior to Closing),

• the existing directors of Thunder Bridge II having resigned and nine directors as set forth in the MTA having been appointed or elected to the Company Board in accordance with the DGCL,

• the completion of the Domestication immediately prior to the Business Combination,

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• after giving effect to the Redemptions, there being at least $262,185,126 remaining in the Trust Account, before expenses,

• the PIPE Financing shall have raised at least $75,000,000,

• after giving effect to any Redemptions and the PIPE Financing, Surviving Pubco having at least $250,000,000 in cash and cash equivalents, and

• the Sponsor has delivered the shares into escrow to be held subject to earnout conditions.

See the section entitled “Shareholder Proposal 2: The Merger Proposal” for a summary of the terms of the MTA and additional information regarding the terms of the Merger Proposal.

Organizational Structure

Prior to the Business Combination

The diagrams below depict simplified versions of the current organizational structures of Surviving Pubco, Thunder Bridge II and indie, respectively.

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After the Business Combination

The diagram below depicts a simplified version of our organizational structure immediately following the completion of the Business Combination.

Our organizational structure following the completion of the Business Combination, as described above, is commonly referred to as an umbrella partnership-C (or Up-C) corporation structure. This organizational structure will allow certain indie Equity Holders to retain their equity ownership in indie, an entity that is classified as a partnership for U.S. federal income tax purposes, in the form of Post-Merger indie Units. Those investors who, prior to the Business Combination, held Class A ordinary shares or Class B ordinary shares of Thunder Bridge II will, by contrast, hold their equity ownership in Surviving Pubco, a Delaware corporation that is a domestic corporation for U.S. federal income tax purposes. We believe that the indie Equity Holders that retain Post-Merger indie Units will generally find it advantageous to continue to hold their equity interests in an entity that is not taxable as a corporation for U.S. federal income tax purposes. We do not believe that our Up-C corporation structure will give rise to any significant business or strategic benefit or detriment to us. See the section entitled “Risk Factors — Risks Related to the Domestication and the Business Combination” for additional information on our organizational structure, including the Tax Receivable Agreement and Exchange Agreement.

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Other Agreements Relating to the Business Combination

Tax Receivable Agreement

Following the Closing, pursuant to a Tax Receivable Agreement between the Company and certain holders of Post-Merger indie Units, the Company will pay to such holders 85% of the tax savings that the Company realizes due to increases in the tax basis in indie’s assets as a result of the exchange of the Post-Merger indie Units for shares of Class A common stock and certain tax attributes of the ADK Blocker Group and tax benefits related to entering into the Tax Receivable Agreement, including tax benefits attributable to payments under the Tax Receivable Agreement. For more information on the Tax Receivable Agreement, please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Tax Receivable Agreement.”

Exchange Agreement

Following the Closing, pursuant to an Exchange Agreement between the Company and certain holders of Post-Merger indie Units, at any time after the six month anniversary of the Closing, each such holder of Post-Merger indie Units (including Post-Merger indie Units received as Earn Out Shares) will be entitled to exchange such units for Class A common stock of the Company on a one-for-one basis (subject to customary conversion rate adjustments, including for stock splits, stock dividends and reclassifications). Based on the assumptions set forth under the section entitled “Frequently Used Terms — Share Calculations and Ownership Percentages,” the total number of Post-Merger indie Units issuable will be 40,243,644, entitling such holders collectively to exchange them for 27.2% of the Company’s Class A common stock in the aggregate (assuming no redemptions). For more information on the Exchange Agreement, please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Exchange Agreement.”

Sponsor Letter Agreement

In connection with the Business Combination, the Sponsor has agreed pursuant to the Sponsor Letter Agreement, to hold 3,450,000 of its shares of Class B common stock in escrow subject to forfeiture if the Company does not satisfy the same stock-price based performance thresholds to which the Earn-Out Shares are subject. For more information on the Sponsor Letter Agreement, please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Sponsor Letter Agreement.”

Sponsor Support Agreement

Simultaneously with the execution of the MTA, the Sponsor entered into the Sponsor Support Agreement, dated December 14, 2020 (the “Sponsor Support Agreement”) in favor of indie, where the Sponsor agreed to vote all of its Thunder Bridge II ordinary shares in favor of the Business Combination and related transactions and to take certain other actions in support of the MTA and related transactions. The Sponsor Support Agreement also prevents the Sponsor from transferring its voting rights with respect to its Thunder Bridge II ordinary shares or otherwise transferring its Thunder Bridge II ordinary shares prior to the Shareholders Meeting, except for certain permitted transfers. For more information on the Sponsor Support Agreement, please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Sponsor Support Agreement.”

Company Support Agreement

Simultaneously with the execution of the MTA, certain officers and directors of indie and certain indie Equity Holders entered into support agreements (collectively, the “Company Support Agreements”) in favor of Thunder Bridge II and the Company and their present and future successors and subsidiaries.

In the Company Support Agreements, the officers and directors and indie Equity Holders party thereto, each agreed to vote all of their indie membership interests in favor of the Business Combination and related transactions and to take certain other actions in support of the MTA and related transactions. The Support Agreements also prevent them from transferring their voting rights with respect to their indie membership interests or otherwise transferring their indie membership interests prior to the meeting of indie’s Equity Holders to approve the MTA and related transactions, except for certain permitted transfers. For more information on the Company Support Agreements, please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Company Support Agreements.”

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Subscription Agreements

Contemporaneously with the execution of the MTA, Thunder Bridge II entered into separate Subscription Agreements with a number of subscribers (the “PIPE Investors”), pursuant to which the subscribers agreed to purchase, and Thunder Bridge II agreed to sell, an aggregate of up to 15,000,000 shares of Class A common stock of the Company (the “PIPE Shares”), in a private placement for a purchase price of $10.00 per share and an aggregate purchase price of $150 million (the “PIPE Financing”). Such shares, if unrestricted and freely tradable, would have an aggregate market value of approximately $151.8 million based on the last sale price of $10.12 per share on Nasdaq on May 10, 2021.

The closing of the sale of the PIPE Shares pursuant to the Subscription Agreements is contingent upon, among other customary closing conditions, the substantially concurrent Closing of the Business Combination. The purpose of the PIPE Financing is to raise additional capital for use by the Company following the Closing.

Pursuant to the Subscription Agreements, Thunder Bridge II agreed that, within 30 calendar days after the Closing, the Company will file with the SEC (at the Company’s sole cost and expense) a registration statement registering the resale of the PIPE Shares, and the Company shall use its commercially reasonable efforts to have such registration statement declared effective as soon as practicable after the filing thereof, but no later than the earlier of (i) the 90th calendar day (or 120th calendar day if the SEC notifies the Company that it will “review” the registration statement) following the Closing and (ii) the fifth business day after the date the Company is notified (orally or in writing, whichever is earlier) by the SEC that the registration statement will not be “reviewed” or will not be subject to further review.

For more information on the Subscription Agreements, please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Subscription Agreements.”

Shareholder Proposal 3: The Equity Incentive Plan Proposal

Thunder Bridge II is proposing that its shareholders approve the 2021 Equity Incentive Plan, which will become effective upon the Closing and will be used by the Company on a going-forward basis following the Closing. A summary of the 2021 Equity Incentive Plan is set forth in the section entitled “Shareholder Proposal 3: The Equity Incentive Plan Proposal” of this proxy statement/prospectus and a complete copy of the 2021 Equity Incentive Plan is attached hereto as Annex C.

Shareholder Proposal 4: The Director Election Proposal

Thunder Bridge II is proposing that its shareholders approve the election of nine directors to serve staggered terms on the Company Board until the 2022, 2023 and 2024 annual meeting of stockholders, respectively, and until their respective successors are duly elected and qualified. A summary of the Director Election Proposal is set forth in the section entitled “Shareholder Proposal 4: The Director Election Proposal” of this proxy statement/prospectus.

Shareholder Proposal 5: The Nasdaq Proposal

Thunder Bridge II is proposing that its shareholders approve, (i) for purposes of complying with Nasdaq Listing Rules 5635(a) and (b), the issuance of more than 20% of the issued and outstanding Class A common stock and the resulting change in control in connection with the Business Combination, and (ii) for the purposes of complying with Nasdaq Listing Rules 5635(d) the issuance of more than 20% of the issued and outstanding Class A ordinary shares in the PIPE Financing (as defined in the accompanying proxy statement/prospectus), upon the completion of the Business Combination. A summary of the Nasdaq Proposal is set forth in the section entitled “Shareholder Proposal 5: The Nasdaq Proposal” of this proxy statement/prospectus.

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Shareholder Proposal 6: The Advisory Charter Proposals

Thunder Bridge II is proposing that its shareholders vote to approve and adopt, on a non-binding advisory basis, certain differences between Thunder Bridge II’s current Memorandum and Articles of Association (the “existing charter”) and the proposed charter, which are being presented in accordance with the requirements of the U.S. Securities and Exchange Commission (the “SEC”) as nine separate sub-proposals (which we refer to, collectively, as the “Advisory Charter Proposals”). By presenting these proposals separately, we intend to provide stockholders a means to communicate their separate views on important governance provisions to the Board:

(D) Advisory Charter Proposal D — provide that the Company’s board of directors will be divided into three classes designated as Class I, Class II and Class III.

(E) Advisory Charter Proposal E — provide that directors may be elected by the stockholders only at an annual meeting of stockholders by a plurality of the votes cast.

Shareholder Proposal 7: The Shareholder Adjournment Proposal

The Shareholder Adjournment Proposal, if adopted, will allow the Thunder Bridge II Board to adjourn the Shareholders Meeting to a later date or dates, including, if necessary to permit further solicitation and vote of proxies if it is determined by Thunder Bridge II that more time is necessary or appropriate to approve one or more Shareholder Proposals at the Shareholders Meeting. A summary of the Shareholder Adjournment Proposal is set forth in the section entitled “Shareholder Proposal 6: The Shareholder Adjournment Proposal” of this proxy statement/prospectus.

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The Shareholders Meeting

Date, Time and Place of Shareholders Meeting

The Shareholders Meeting will be held at 101 Constitution Ave, NW, Suite 900, Washington, DC 20001, USA at 11:00 a.m. Eastern Time, on June 9, 2021, or at such other date, time and place to which such meeting may be adjourned and also via live webcast at https://www.cstproxy.com/thunderbridgeacquisitionii/sm2021 to consider and vote upon the Shareholder Proposals, as a virtual meeting.

Record Date; Outstanding Shares; Shareholders Entitled to Vote

Thunder Bridge II has fixed the close of business on May 10, 2021, as the Record Date for determining the Thunder Bridge II shareholders entitled to notice of and to attend and vote at the Shareholders Meeting.

As of the close of business on such date, there were 34,500,000 Class A ordinary shares and 8,625,000 Founder Shares outstanding and entitled to vote. The Class A ordinary shares and the Founder Shares vote together as a single class, except in the election of directors, as to which only the Founder Shares vote, and each share is entitled to one vote per share at the Shareholders Meeting. The Sponsor owns 8,625,000 Founder Shares, which are Class B ordinary shares of Thunder Bridge II. Pursuant to the Insider Letter Agreement among Thunder Bridge II, the Sponsor and Thunder Bridge II’s directors and officers, (i) the 8,625,000 Founder Shares owned by the Sponsor and (ii) any other ordinary shares of Thunder Bridge II owned by the Sponsor or Thunder Bridge II’s officers and directors will be voted in favor of the Merger Proposal at the Shareholders Meeting. Pursuant to the Sponsor Support Agreement, the Sponsor has agreed to vote its Founder Shares and any other ordinary shares of Thunder Bridge II owned by it in favor of each of the Shareholder Proposals.

Proxy Solicitation

Proxies with respect to the Shareholders Meeting may be solicited by telephone, by facsimile, by mail, on the internet or in person. Thunder Bridge II has engaged Morrow Sodali LLC to assist in the solicitation of proxies. If a shareholder grants a proxy, it may still vote its shares at the virtual meeting if it revokes its proxy before the Shareholders Meeting. A shareholder may also change its vote by submitting a later-dated proxy, as described in the section entitled “Shareholders Meeting — Revoking Your Proxy — Changing Your Vote.”

Quorum and Required Vote

A quorum of Thunder Bridge II shareholders is necessary to hold the Shareholders Meeting. The presence, in person or by proxy, of Thunder Bridge II shareholders representing a majority of the ordinary shares issued and outstanding on the Record Date and entitled to vote on the Shareholder Proposals to be considered at the Shareholders Meeting will constitute a quorum for the Shareholders Meeting.

Each of the Domestication Proposal, the Merger Proposal, the Equity Incentive Plan Proposal, the Director Election Proposal, and the Nasdaq Proposal is interdependent upon the others and must be approved in order for Thunder Bridge II to complete the Business Combination as contemplated by the MTA. The Merger Proposal, the Equity Incentive Plan Proposal, the Nasdaq Proposal, the Advisory Charter Proposals and the Shareholder Adjournment Proposal will require an ordinary resolution under Cayman Islands law, being the affirmative vote of the holders of a majority of the Thunder Bridge II Shares that are present and vote at the Shareholders Meeting. The Domestication Proposal must be approved by a special resolution under Cayman Islands law, being the affirmative vote of the holders of at least two-thirds of the Thunder Bridge II Shares as of the Record Date that are present and vote at the Shareholders Meeting. The election of directors pursuant to the Director Election Proposal will require an ordinary resolution of the holders of the Founder Shares only as a matter of Cayman Islands law, being the affirmative vote of the holders of a majority of the Thunder Bridge II Class B ordinary shares that are present and vote at the Shareholders Meeting.

Regulatory Approvals

The Business Combination and the transactions contemplated by the MTA are not subject to any regulatory requirement or approval, except for (i) filings with the Cayman Islands and the State of Delaware necessary to effectuate the Domestication, (ii) filings with the State of Delaware to effect the Mergers, (iii) filings required with the SEC pursuant to the reporting requirements applicable to Thunder Bridge II and Surviving Pubco, and the

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requirements of the Securities Act and the Exchange Act, including the requirement to file the registration statement of which this proxy statement/prospectus forms a part and to disseminate this proxy statement/prospectus to Thunder Bridge II’s shareholders and (iv) filings required under the HSR Act in connection with the Business Combination. Thunder Bridge II must comply with applicable United States federal and state securities laws in connection with the Domestication, including the filing with Nasdaq of a press release disclosing the Domestication and Business Combination, among other things.

Appraisal Rights

Thunder Bridge II’s shareholders do not have appraisal rights under the Companies Act or otherwise in connection with the Merger Proposal or the other Shareholder Proposals.

Redemption Rights

Under Section 49.2 of Thunder Bridge II’s Memorandum and Articles of Association, prior to the completion of the Business Combination, Thunder Bridge II will provide all of the Public Shareholders with the opportunity to have their shares redeemed upon the completion of the Business Combination, subject to certain limitations, for cash equal to the applicable Redemption Price; provided, however, that Thunder Bridge II may not redeem such shares to the extent that such Redemption would result in Thunder Bridge II having net tangible assets (as determined under the Exchange Act) of less than $5,000,001 upon the completion of the Business Combination.

Public Shareholders may seek to have their shares redeemed regardless of whether they vote for or against the Business Combination, whether or not they were holders of Thunder Bridge II ordinary shares as of the Record Date or acquired their shares after the Record Date. The Redemptions will be effectuated in accordance with the Memorandum and Articles of Association and Cayman Islands law. Any Public Shareholder who holds ordinary shares of Thunder Bridge II on or before June 7, 2021 (two business days before the Shareholders Meeting) will have the right to demand that his, her or its shares be redeemed for a pro rata share of the aggregate amount then on deposit in the Trust Account, less any taxes then due but not yet paid, at the completion of the Business Combination); provided that such Public Shareholders follow the procedures provided for exercising such Redemption as set forth in the Memorandum and Articles of Association, as described below, by such date. However, the proceeds held in the Trust Account could be subject to claims that could take priority over those of Public Shareholders exercising Redemption Rights, regardless of whether such holders vote for or against the Merger Proposal and whether such holders are holders of Thunder Bridge II ordinary shares as of the Record Date. Therefore, the per-share distribution from the Trust Account in such a situation may be less than originally anticipated due to such claims. A Public Shareholder will be entitled to receive cash for these shares only if the Business Combination is completed.

Material U.S. Federal Income Tax Consequences

As discussed more fully under the section entitled “Shareholder Proposal 2: The Merger Proposal — Material U.S. Federal Income Tax Consequences of the Domestication to Thunder Bridge II Shareholders” below, it is intended that the Domestication will constitute a tax-free reorganization within the meaning of Section 368(a)(l)(F) of the Code. Assuming that the Domestication so qualifies, U.S. Holders (as defined in such section) of Thunder Bridge II Shares will be subject to Section 367(b) of the Code and, as a result:

• A U.S. Holder of Thunder Bridge II Shares whose Thunder Bridge II Shares have a fair market value of less than $50,000 on the date of the Domestication will not recognize any gain or loss and will not be required to include any part of Thunder Bridge II’s earnings in income;

• A U.S. Holder of Thunder Bridge II Shares whose Thunder Bridge II Shares have a fair market value of $50,000 or more, but who on the date of the Domestication owns (actually and constructively) less than 10% of the total combined voting power of all classes of Thunder Bridge II Shares entitled to vote will generally recognize gain (but not loss) on the exchange of Thunder Bridge II Shares for shares in the Company (a Delaware corporation) pursuant to the Domestication. As an alternative to recognizing gain, such U.S. Holders may file an election to include in income as a dividend the “all earnings and profits amounts,” (as defined in Treasury Regulation Section 1.367(b)-2(d)) attributable to their Thunder Bridge II Shares, provided certain other requirements are satisfied. Thunder Bridge II does not expect to have significant cumulative earnings and profits, if any, on the date of the Domestication; and

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• A U.S. Holder of Thunder Bridge II Shares whose Thunder Bridge II Shares have a fair market value of $50,000 or more, and who on the date of the Domestication owns (actually and constructively) 10% or more of the total combined voting power of all classes of Thunder Bridge II Shares entitled to vote will generally be required to include in income as a dividend the “all earnings and profits amount,” (as defined in Treasury Regulation Section 1.367(b)-2(d)) attributable to its Thunder Bridge II Shares, provided certain other requirements are satisfied. Thunder Bridge II does not expect to have significant cumulative earnings and profits, if any, on the date of the Domestication.

Furthermore, even if the Domestication qualifies as a reorganization under Section 368(a) of the Code, a U.S. Holder of Thunder Bridge II Shares may still recognize gain (but not loss) upon the exchange of its Thunder Bridge II Shares for the common stock of the Delaware corporation pursuant to the Domestication under the “passive foreign investment company,” or PFIC, rules of the Code equal to the excess, if any, of the fair market value of the common stock of the Delaware corporation received in the Domestication and the U.S. Holder’s adjusted tax basis in the corresponding Thunder Bridge II Shares surrendered in exchange therefor. The tax on any such gain so recognized would be imposed at the rate applicable to ordinary income and an interest charge would apply. In such event, the U.S. Holder’s aggregate tax basis in the common stock of the Delaware corporation received in connection with the Domestication should be the same as the aggregate tax basis of Thunder Bridge II Shares surrendered in the transaction, increased by any amount included in the income of such U.S. Holder under the PFIC rules. For a more complete discussion of the potential application of the PFIC rules to U.S. Holders as a result of the Domestication, see the discussion in the section entitled “Shareholder Proposal 2: The Merger Proposal — Material U.S. Federal Income Tax Consequences of the Domestication to Thunder Bridge II Shareholders — U.S. Holders PFIC Considerations.”

For a description of the tax consequences for Public Shareholders holders exercising Redemption Rights in connection with the Business Combination, see the sections entitled “Shareholder Proposal 2: The Merger Proposal — Material U.S. Federal Income Tax Consequences of the Domestication to Thunder Bridge II Shareholders and Warrant Holders — Tax Consequences to U.S. Holders That Elect to Have Their Thunder Bridge II Shares Converted for Cash” and “Shareholder Proposal 2: The Merger Proposal — Material U.S. Federal Income Tax Consequences of the Domestication to Thunder Bridge II Shareholders and Warrant Holders — Tax Consequences to Non-U.S. Holders That Elect to Have Their Thunder Bridge II Shares Converted for Cash.”

Anticipated Accounting Treatment of the Business Combination

The Business Combination will be accounted for as a reverse recapitalization, in accordance with GAAP. Under this method of accounting, although Thunder Bridge II will issue shares for outstanding equity interests of indie in the Business Combination, Thunder Bridge II will be treated as the “acquired” company for financial reporting purposes. Accordingly, the Business Combination will be treated as the equivalent of indie issuing stock for the net assets of Thunder Bridge II, accompanied by a recapitalization. The net assets of Thunder Bridge II will be stated at historical cost, with no goodwill or other intangible assets recorded. Operations prior to the Business Combination will be those of indie.

Interests of Certain Persons in the Business Combination

When you consider the recommendation of the Thunder Bridge II Board in favor of adoption of the Domestication Proposal and the Merger Proposal, you should keep in mind that Thunder Bridge II’s directors and officers have interests in the Business Combination that are different from, or in addition to, your interests as a shareholder. The existence of any financial and personal interests of one or more of Thunder Bridge II’s directors may be argued to result in a conflict of interest on the part of such director(s) between what he, she or they may believe is in the best interests of Thunder Bridge II and its shareholders and what he, she or they may believe is best for himself, herself or themselves in determining to recommend that shareholders vote for the Shareholder Proposals. See the section entitled “Shareholder Proposal 2: The Merger Proposal — Interests of Thunder Bridge II’s Directors and Officers and Others in the Business Combination” in this proxy statement/prospectus for a further discussion of such interests and potential conflicts of interest.

Going Concern

Primarily as a result of ongoing product development investments, indie has incurred recurring losses and negative cash flows from operating activities since its inception, including net operating losses of $19.2 million and $18.9 million for the years ended December 31, 2020 and 2019, respectively. Net losses, which among other things include the impact

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of fair value changes in indie’s SAFE liabilities and interest expenses, were $98.4 million and $20.9 million, for the years ended December 31, 2020 and 2019, respectively. As of December 31, 2020, indie had an accumulated deficit of $153.3 million. indie expects to continue to invest in product development and generate operating losses in the future.

If the proposed Business Combination is not consummated, indie would require additional funding to sustain operations over the next twelve months and execute its business plan. Accordingly, indie’s auditor’s report includes an explanatory paragraph expressing substantial doubt about indie’s ability to continue as a going concern. See “Risk Factors — Risks Related to indie’s Business — indie’s independent registered public accounting firm, KPMG LLP’s, report contains an explanatory paragraph that expresses substantial doubt about indie’s ability to continue as a ‘going concern.’”

Risk Factors

In evaluating the Shareholder Proposals set forth in this proxy statement/prospectus, you should carefully read this proxy statement/prospectus, including the annexes, and especially consider the factors discussed in the section entitled “Risk Factors” beginning on page 44.

Risk Factors Summary

The transactions described in this proxy statement/consent solicitation statement/prospectus involve various risks, and you should carefully read and consider the factors discussed under “Risk Factors.” The following is a summary of some of these risks.

Risks Related to the Domestication and the Business Combination

• Thunder Bridge II’s shareholders will experience dilution due to the issuance of shares of Class A common stock securities convertible into the shares of Class A common stock of the Company to the indie Equity Holders as consideration in the Mergers, the issuance of shares to the PIPE Investors in the PIPE Financing.

• The ability of Thunder Bridge II’s shareholders to exercise Redemption Rights with respect to Thunder Bridge II’s Public Shares may prevent Thunder Bridge II from completing the Business Combination or optimizing its capital structure.

• Subsequent to the completion of the Business Combination, the Company may be required to take write-downs or write-offs, restructuring and impairment or other charges that could have a significant negative effect on its financial condition and its share price, which could cause you to lose some or all of your investment.

• The Company’s ability to be successful following the Business Combination will depend upon the efforts of the Company Board and indie’s key personnel and the loss of such persons could negatively impact the operations and profitability of the Company’s business following the Business Combination.

• The Company will be a holding company and its only material asset after completion of the Business Combination will be its interest in indie, and it is accordingly dependent upon distributions made by its subsidiaries to pay taxes, make payments under the Tax Receivable Agreement and pay dividends.

• Under the Tax Receivable Agreement, the Company will be required to pay 85% of the tax benefits relating to tax depreciation or amortization deductions as a result of the tax basis step-up and certain tax attributes of the ADK Blocker Group the Company receives in connection with the exchanges of Post-Merger indie Units into the Company’s Class A common stock and related transactions, those payments may be substantial, and in certain cases, payments under the Tax Receivable Agreement may exceed the actual tax benefits the Company realizes or may be accelerated.

• Some of Thunder Bridge II’s officers and directors may have conflicts of interest that may influence or have influenced them to support or approve the Business Combination.

• Thunder Bridge II has not obtained an opinion from an independent investment banking firm or another independent firm, and consequently, you may have no assurance from an independent source that the terms of the Business Combination are fair to Thunder Bridge II from a financial point of view.

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• There is a minimum cash requirement and maximum redemption threshold and other conditions in the MTA, and failure to satisfy these conditions will stop our ability to consummate the Business Combination.

• Nasdaq may delist the Company’s securities from trading on its exchange, which could limit investors’ ability to make transactions in the Company’s securities and subject the Company to additional trading restrictions.

• The unaudited pro forma financial information included in the section entitled “Unaudited Pro Forma Condensed Combined Financial Information” may not be representative of the Company’s results if the Business Combination is completed.

• Thunder Bridge II will not be able to enter into a business combination with another party because of restrictions in the MTA and certain provisions of the MTA will discourage third parties from submitting superior alternative takeover proposals.

• Because Thunder Bridge II is incorporated under the laws of the Cayman Islands, in the event the Business Combination is not completed, you may face difficulties in protecting your interests, and your ability to protect your rights through the U.S. federal courts may be limited.

• There is a risk that a U.S. Holder may recognize taxable gain with respect to its Thunder Bridge II Shares at the effective time of the Domestication and the rights of holders of the Company’s common stock arising under the DGCL after the Business Combination will differ from and may be less favorable to the rights of holders of Thunder Bridge II’s ordinary shares arising under the Cayman Islands Companies Act.

• Delaware law and the Certificate of Incorporation and Bylaws will contain certain provisions, including anti-takeover provisions that limit the ability of stockholders to take certain actions and could delay or discourage takeover attempts that stockholders may consider favourable, and will designate the Court of Chancery of the State of Delaware as the sole and exclusive forum for certain types of actions and proceedings that may be initiated by our stockholders, which could limit our stockholders’ ability to obtain a favorable judicial forum for disputes with the Company or the Company’s directors, officers or other employees.

• The Certificate of Incorporation will not limit the ability of the Sponsor to compete with us.

• Thunder Bridge II’s officers and directors and/or their affiliates may enter into agreements concerning Thunder Bridge II’s securities prior to the Shareholders Meeting, which may have the effect of increasing the likelihood of completion of the Business Combination or decreasing the value of the Thunder Bridge II Shares.

• The Company’s business and operations could be negatively affected if it becomes subject to any securities litigation or shareholder activism, which could cause the Company to incur significant expense, hinder execution of business and growth strategy and impact its stock price.

Risks Related to indie’s Business

• The cyclical nature of the semiconductor industry may limit indie’s ability to maintain or improve its net sales and profitability.

• Downturns or volatility in general economic conditions could have a material adverse effect on indie’s business, financial condition, results of operations and liquidity.

• The semiconductor industry is highly competitive. If indie fails to introduce new technologies and products in a timely manner, it could adversely affect business.

• The average selling prices of products in indie’s markets have historically decreased over time and could do so in the future, which could adversely impact indie’s revenue and profitability.

• Much of indie’s business depends on winning competitive bid selection processes, and failure to be selected could adversely affect business in those market segments.

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• The demand for indie’s products depends to a significant degree on the demand for its customers’ end products and any downturn in the automotive market could significantly harm indie’s financial results.

• indie may be unsuccessful in developing and selling new products with profit margins similar to or better than what it has experienced in the past, which would impact indie’s overall financial performance.

• indie’s failure to comply with the large body of laws and regulations to which it is subject could have a material adverse effect its business and operations.

• indie may require additional capital to support business, and this capital might not be available on acceptable terms, if at all.

• indie may face risks related to cyber security, information technology systems, protecting its intellectual property and risks of third parties alleging infringement of intellectual property rights.

• indie may rely on strategic partnerships, joint ventures and alliances for manufacturing and research and development and actions taken by any of its partners or the termination of these partnerships or joint ventures could adversely affect business.

• indie may from time to time desire to exit certain programs or businesses, or to restructure its operations, but may not be successful in doing so.

• indie’s working capital levels are difficult to manage and predict.

• indie’s business may be adversely affected by costs relating to product defects, and indie could be faced with product liability claims and warranty claims.

• indie’s business could be adversely affected by losses of key employees, key customers, suppliers or third-party manufacturing partners.

• Significant litigation could impair indie’s reputation and cause it to incur substantial costs.

• indie faces risks related to export controls and trade regulation, tax, and related regulations.

• indie may pursue mergers, acquisitions, investments and joint ventures, which could adversely affect its results of operations.

• Inadequate internal controls could result in inaccurate financial reporting.

• Amounts disclosed as “strategic backlog” and “design win pipeline” may not result in actual revenue or translate into profits.

• Conflict minerals disclosure regulations may force indie to incur additional expenses, may result in damage to its business reputation and may adversely impact its ability to conduct its business.

• indie could be adversely affected by violations of applicable anti-corruption laws or violations of its internal policies designed to ensure ethical business practices.

• Fluctuations in foreign exchange rates could have an adverse effect on indie’s results of operations.

• Certain software that indie uses in its products is licensed from third parties and may not be available to indie in the future, which may delay product development and production or cause indie to incur additional expense.

• indie’s worldwide operations are subject to political, economic and health risks and natural disasters, which could have a material adverse effect on business operations.

• indie’s operating results are subject to substantial quarterly and annual fluctuations.

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Risks Related to Thunder Bridge II

• You have limited rights or interests in funds in the Trust Account. To liquidate your investment, therefore, you may be forced to sell your Public Shares or warrants, potentially at a loss.

• Thunder Bridge II’s shareholders may be held liable for claims by third parties against Thunder Bridge II to the extent of distributions received by them upon Redemption of their shares or in the event of bankruptcy.

• If third parties bring claims against Thunder Bridge II, the proceeds held in the Trust Account could be reduced and the Redemption Price received by Public Shareholders may be less than $10.00 per share.

• Thunder Bridge II’s directors may decide not to enforce the indemnification obligations of the Sponsor under the Insider Letter Agreement, resulting in a reduction in the amount of funds in the Trust Account available for distribution to Thunder Bridge II’s Public Shareholders and the Insider Letter Agreement may be amended without shareholder approval.

• Changes in laws or regulations, or a failure to comply with any laws and regulations, may adversely affect the business, investments and results of operations of Thunder Bridge II.

• Thunder Bridge II’s founder and chief executive officer controls a substantial interest in Thunder Bridge II and thus may exert a substantial influence on actions requiring a shareholder vote, potentially in a manner that you do not support.

• The terms of the Warrants may be amended in a manner that may be adverse to holders with the approval by the holders of at least a majority of the then outstanding Public Warrants and the Warrant may have an adverse effect on the market price of the Company’s Class A common stock.

• Your unexpired Warrants may be redeemed prior to their exercise at a time that is disadvantageous to you, thereby making your Warrants worthless.

• indie and Thunder Bridge II each qualify as an “emerging growth company” within the meaning of the Securities Act, and if they takes advantage of certain exemptions from disclosure requirements available to emerging growth companies, it could make its securities less attractive to investors and may make it more difficult to compare its performance to the performance of other public companies.

• Compliance obligations under the Sarbanes-Oxley Act may make it more difficult for Thunder Bridge II to effectuate the Business Combination, require substantial financial and management resources and increase the time and costs of completing an acquisition.

Recommendation to Shareholders of Thunder Bridge II

The Thunder Bridge II Board has unanimously approved the Shareholder Proposals.

The Thunder Bridge II Board unanimously recommends that shareholders:

• Vote “FOR” the Domestication Proposal;

• Vote “FOR” the Merger Proposal;

• Vote “FOR” the Equity Incentive Plan Proposal;

• Vote “FOR” the election of each of the directors pursuant to the Director Election Proposal;

• Vote “FOR” the Nasdaq Proposal;

• Vote “FOR” each of the Advisory Charter Proposals; and

• Vote “FOR” the Shareholder Adjournment Proposal, if it is presented at the Shareholders Meeting.

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QUESTIONS AND ANSWERS

Q. Why am I receiving this proxy statement/prospectus?

A. You are receiving this proxy statement/prospectus in connection with the virtual extraordinary general meeting of Thunder Bridge II. Thunder Bridge II is holding the Shareholders Meeting to consider and vote upon the Shareholder Proposals described below. Your vote is important. You are encouraged to vote as soon as possible after carefully reviewing this proxy statement/prospectus.

Thunder Bridge II’s shareholders are being asked to consider and vote upon the Domestication Proposal, the Merger Proposal, the Equity Incentive Plan Proposal, the Nasdaq Proposal, the Advisory Charter Proposals and, if presented, the Shareholder Adjournment Proposal. Holders of Thunder Bridge II’s Class B ordinary shares are also being asked to consider and vote upon the Director Election Proposal.

The presence, in person or by proxy, of Thunder Bridge II shareholders representing a majority of the issued and outstanding ordinary shares on the Record Date and entitled to vote on the Shareholder Proposals to be considered at the Shareholders Meeting, including a majority of the issued and outstanding Class B ordinary shares as of the Record Date in the case of the Director Election Proposal, will constitute a quorum for the Shareholders Meeting.

YOUR VOTE IS IMPORTANT. YOU ARE ENCOURAGED TO VOTE AS SOON AS POSSIBLE AFTER CAREFULLY REVIEWING THIS PROXY STATEMENT/PROSPECTUS.

Q: What is being voted on at the Shareholders Meeting?

A: At the Shareholders Meeting, the shareholders of Thunder Bridge II are being asked to vote on the following Shareholder Proposals:

• Proposal 1 — The Domestication Proposal;

• Proposal 2 — The Merger Proposal;

• Proposal 3 — The Equity Incentive Plan Proposal;

• Proposal 4 — The Director Election Proposal;

• Proposal 5 — The Nasdaq Proposal;

• Proposal 6 — The Advisory Charter Proposals; and

• Proposal 7 — The Shareholder Adjournment Proposal, if presented.

Q: Are the Shareholder Proposals conditioned on one another?

A: Each of the Domestication Proposal, the Merger Proposal, the Equity Incentive Plan Proposal, the Director Election Proposal, and the Nasdaq Proposal is interdependent upon the others and each must be approved in order for Thunder Bridge II to complete the Business Combination contemplated by the MTA.

Q: What vote is required to approve the Shareholder Proposals?

A: Proposal 1 — The Domestication Proposal must be approved by a special resolution under Cayman Islands law, being the affirmative vote of the holders of at least two-thirds of the Thunder Bridge II ordinary shares as of the Record Date that are present and vote at the Shareholders Meeting.

Proposal 2 — The Merger Proposal must be approved by an ordinary resolution under Cayman Islands law, being the affirmative vote of the holders a majority of the Thunder Bridge II ordinary shares as of the Record Date that are present and vote at the Shareholders Meeting.

Proposal 3 — The Equity Incentive Plan Proposal must be approved by an ordinary resolution under Cayman Islands law, being the affirmative vote of the holders a majority of the Thunder Bridge II ordinary shares as of the Record Date s that are present and vote at the Shareholders Meeting.

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Proposal 4 — The election of directors pursuant to the Director Election Proposal will require must be approved by an ordinary resolution by the holders of the Thunder Bridge II Class B ordinary shares under Cayman Islands law, being the affirmative vote of the holders of a majority of the Thunder Bridge II Class B ordinary shares that are present and vote at the Shareholders Meeting.

Proposal 5 — The Nasdaq Proposal must be approved by an ordinary resolution under Cayman Islands law, being the affirmative vote of the holders a majority of the Thunder Bridge II ordinary shares as of the Record Date that are present and vote at the Shareholders Meeting.

Proposal 6 — Each of the Advisory Charter Proposals, each of which is a non-binding vote, must be approved by an ordinary resolution under Cayman Islands law, being the affirmative vote of the holders a majority of the Thunder Bridge II ordinary shares as of the Record Date that are present and vote at the Shareholders Meeting.

Proposal 7 — The Shareholder Adjournment Proposal must be approved by an ordinary resolution under Cayman Islands law, being the affirmative vote of the holders a majority of the Thunder Bridge II ordinary shares as of the Record Date that are present and vote at the Shareholders Meeting.

Q. Why is Thunder Bridge II proposing the Domestication?

A. The Thunder Bridge II Board believes that it would be in the best interests of Thunder Bridge II to effect the Domestication to enable the Company to lessen certain taxes that would be imposed on the Company if the Company were to conduct an operating business in the United States as a foreign corporation following the Business Combination. In addition, the Thunder Bridge II Board believes Delaware provides a recognized body of corporate law that will facilitate corporate governance by the Company’s officers and directors. Delaware maintains a favorable legal and regulatory environment in which to operate. For many years, Delaware has followed a policy of encouraging companies to incorporate there and, in furtherance of that policy, has adopted comprehensive, modern and flexible corporate laws that are regularly updated and revised to meet changing business needs. In addition, the Delaware courts have developed a considerable expertise in dealing with corporate issues and a substantial body of case law has developed construing the DGCL and establishing public policies with respect to Delaware corporations. As a result, many major corporations have initially chosen Delaware as their domicile or have subsequently reincorporated in Delaware in a manner similar to the procedures Thunder Bridge II is proposing.

The Domestication will not occur unless the Thunder Bridge II shareholders have approved the Domestication Proposal, the Merger Proposal, the Equity Incentive Plan Proposal, the Director Election Proposal, and the Nasdaq Proposal. The Domestication will only occur simultaneously with the Business Combination.

Q. What is involved with the Domestication?

A. The Domestication will require Thunder Bridge II to file certain documents in both the Cayman Islands and the State of Delaware. At the effective time of the Domestication, which will be the effective time of the Business Combination, Thunder Bridge II will cease to be a company incorporated under the laws of the Cayman Islands and in connection with Domestication, Thunder Bridge II will continue as a Delaware corporation and will change its corporate name to “Indie Acquisition Company II, Corp.” The Memorandum and Articles of Association will be replaced by the Certificate of Incorporation and Bylaws and your rights as a shareholder will cease to be governed by the laws of the Cayman Islands and will be governed by Delaware law. Simultaneous with the Domestication, in connection with the Business Combination, the securities of Thunder Bridge II will be exchanged for corresponding securities in the Company, with the Company succeeding as successor registrant and public company issuer pursuant to the federal securities laws and changing its name to indie Semiconductor, Inc.

Q. When do you expect that the Domestication will be effective?

A. The Domestication is expected to become effective simultaneously with the completion of the Business Combination.

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Q. How will the Domestication and Business Combination affect my securities of Thunder Bridge II?

A. Pursuant to the Domestication and Business Combination and without further action on the part of Thunder Bridge II’s shareholders, each outstanding Class A ordinary share and Class B ordinary share of Thunder Bridge II will be exchanged for one outstanding share of the Company’s Class A common stock, and each warrant to purchase Thunder Bridge II Class A ordinary shares will be exchanged for one warrant to purchase Company Class A common stock at an exercise price of $11.50 per share. Although it will not be necessary for you to exchange your certificates representing ordinary shares after the Domestication, the Company will, upon request, exchange your Thunder Bridge II share certificates for certificates representing the applicable number of shares of Company’s Class A common stock and all certificates for securities issued after the Domestication and Business Combination will be certificates representing securities of the Company.

Q. What are the material U.S. federal income tax consequences of the Domestication to U.S. Holders of Thunder Bridge II Shares?

A. The Domestication should qualify as a reorganization within the meaning of Section 368(a) of the Code for U.S. federal income tax purposes. If the Domestication qualifies as a reorganization within the meaning of Section 368(a), a U.S. Holder of Thunder Bridge II Shares will be subject to Section 367(b) of the Code and as a result:

• A U.S. Holder of Thunder Bridge II Shares whose Thunder Bridge II Shares have a fair market value of $50,000 or more, and who on the date of the Domestication owns (actually and constructively) 10% or more of the total combined voting power of all classes of Thunder Bridge II Shares entitled to vote will generally be required to include in income as a dividend the “all earnings and profits amount,” (as defined in Treasury Regulation Section 1.367(b)-2(d))) attributable to its Thunder Bridge II Shares, provided certain other requirements are satisfied. Thunder Bridge II does not expect to have significant cumulative earnings and profits, if any, on the date of the Domestication.

Furthermore, even if the Domestication qualifies as a reorganization, the Domestication may be a taxable event to U.S. Holders of Thunder Bridge II Shares under special rules applicable to U.S. Holders who hold shares of a “passive foreign investment company,” or “PFIC” as described in “Shareholder Proposal 2: The Merger Proposal — Material U.S. Federal Income Tax Consequences of the Domestication to Thunder Bridge II Shareholders — U.S. Holders — PFIC Considerations.” Thunder Bridge II believes it has been treated as a PFIC since its inception. If the Domestication should fail to qualify as a reorganization under Section 368(a), a U.S. Holder of Thunder Bridge II Shares generally would recognize gain or loss with respect to its Thunder Bridge II Shares in an amount equal to the difference, if any, between the fair market value of the corresponding Company Shares received in the Domestication and the U.S. Holder’s adjusted tax basis in its Thunder Bridge II Shares surrendered. For a more complete discussion of the material U.S. federal income tax consequences of the Domestication, see the discussion in the section entitled “Shareholder Proposal 2: The Merger Proposal — Material U.S. Federal Income Tax Consequences of the Domestication to Thunder Bridge II Shareholders and Warrant Holders.”

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Q. What are the material U.S. federal income tax consequences to U.S. Holders that exercise their Redemption Rights?

A. U.S. Holders that elect to exercise their Redemption Rights generally will recognize capital gain or loss equal to the difference between the amount of cash received on the Redemption of the Thunder Bridge II Shares and such U.S. Holder’s adjusted tax basis in such Thunder Bridge II Shares, which generally will be equal to the cost of such Thunder Bridge II Shares. A U.S. Holder who purchased Thunder Bridge II Shares in the IPO generally will have a tax basis in the Thunder Bridge II Shares that were part of the units equal to the portion of the purchase price of such units allocated to the Thunder Bridge II Shares (such allocation based on the relative fair market value of the Thunder Bridge II Shares and the Warrants at the time). However, in certain circumstances, the cash paid to such U.S. Holders will be treated as dividend income for U.S. federal income tax purposes. Moreover, because Thunder Bridge II should be considered a PFIC for U.S. federal income tax purposes, such U.S. Holders may be subjected to special rules applicable to PFICs as described in “Shareholder Proposal 2: The Merger Proposal — Material U.S. Federal Income Tax Consequences of the Domestication to Thunder Bridge II Shareholders — U.S. Holders — PFIC Considerations.” For a more complete discussion of the material U.S. federal income tax consequences to U.S. Holders that elect to exercise their Redemption Rights, see the discussion in the section entitled “Shareholder Proposal 2: The Merger Proposal — Material U.S. Federal Income Tax Consequences of the Domestication to Thunder Bridge II Shareholders — U.S. Holders — Tax Consequences to U.S. Holders That Elect to Have Their Thunder Bridge II Shares Converted for Cash.”

Q. What are the material U.S. federal income tax consequences of the Business Combination to U.S. Holders?

A. Pursuant to the terms set forth in the MTA, subject to the satisfaction or waiver of the conditions to the Closing therein, simultaneously with completion of the Domestication, (1) TBII Merger Sub will merge with and into Thunder Bridge II, with all outstanding securities of Thunder Bridge II being exchanged for corresponding securities in Surviving Pubco, and Surviving Pubco succeeding as successor registrant and public company issuer pursuant to the federal securities laws and changing its name to indie Semiconductor, Inc., (2) ADK Merger Sub will merge with and into indie, with indie surviving as a controlled 72.8% owned subsidiary of Surviving Pubco, (3) the entities in the ADK Blocker Group will merge with and into ADK Blocker Merger Sub, with ADK Blocker Merger Sub being the surviving limited liability company, (4) ADK Service Provider Merger Sub will merge with and into ADK Service Provider Holdco. Each of these steps (1) through (4) should be considered for U.S. federal income tax purposes as integrated steps in a single transaction which qualifies as a transfer of property to a corporation (Surviving Pubco) tax free to the shareholders and each of the corporate parties under Section 351 of the Code. indie will continue as a limited liability company classified as a partnership for U.S. federal income tax purposes, controlled and consolidated by Surviving Pubco and for financial statement purposes under GAAP.

Q. Why is Thunder Bridge II proposing the Business Combination?

A. Thunder Bridge II was organized to effect a merger, capital stock exchange, asset acquisition or other similar business combination with one or more businesses or entities. Since Thunder Bridge II’s organization, the Thunder Bridge II Board has sought to identify suitable candidates in order to effect such a transaction. In its review of indie, the Thunder Bridge II Board considered a variety of factors weighing positively and negatively in connection with the Business Combination. After careful consideration, the Thunder Bridge II Board has determined that the Business Combination presents a highly-attractive business combination opportunity and is in the best interests of Thunder Bridge II shareholders. The Thunder Bridge II Board believes that, based on its review and consideration, the Business Combination with indie presents an opportunity to increase shareholder value. However, there can be no assurance that the anticipated benefits of the Business Combination will be achieved. Thunder Bridge II shareholder approval of the Business Combination is required by the MTA and the Memorandum and Articles of Association as well as to comply with Nasdaq Listing Rule 5635(a), (b) and (d).

Q. What will happen in the Business Combination?

A. The Business Combination consists of a series of transactions pursuant to which (i) Thunder Bridge II will complete the Domestication, (ii) TBII Merger Sub will merge with and into Thunder Bridge II, with all outstanding securities of Thunder Bridge II being exchanged for corresponding securities in Surviving Pubco, and Surviving Pubco succeeding as successor registrant and public company issuer pursuant to the federal

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securities laws and changing its name to indie Semiconductor, Inc., (iii) ADK Merger Sub will merge with and into indie, with indie surviving as a controlled 72.8% owned subsidiary of Surviving Pubco, (iv) the entities in the ADK Blocker Group will merge with and into ADK Blocker Merger Sub, with ADK Blocker Merger Sub being the surviving limited liability company, (v) ADK Service Provider Merger Sub will merge with and into ADK Service Provider Holdco. Upon the completion of the Domestication and the Business Combination, each issued and outstanding Class A ordinary share and Class B ordinary share of Thunder Bridge II will become a share of Class A common stock of the Company, and each issued and outstanding warrant to purchase Class A ordinary shares of Thunder Bridge II will become a warrant to purchase an equal number of shares of Class A common stock of the Company.

Q. What is the form of consideration that the indie Equity Holders and holders of Phantom Equity Units will receive in return for the acquisition of indie by Thunder Bridge II?

Upon the Closing, the indie Equity Holders and holders of indie Phantom Equity Units will have the right to receive (A) $900 million in aggregate value (as adjusted for any amount that Target Companies’ indebtedness exceeds Target Companies’ cash and cash equivalents at Closing) as set forth in the MTA, in the form of (i) shares of Company Class A common stock (valued at $10.00 per share); (ii) Post-Merger indie Units (valued at $10.00 per unit); or (iii) the right to receive shares of Company Class A common stock, or other consideration pursuant to indie’s Phantom Equity Plan, plus (B) the contingent right to receive up to an aggregate of 10,000,000 additional shares of Class A common stock of the Company or Post-Merger indie Units, as applicable, as an earn-out under the MTA after the Closing. Each share of Class A common stock of the Company will provide the holder the right to vote, receive dividends, and share in distributions in connection with a liquidation, and other stockholder rights with respect to the Company.

Pursuant to the Exchange Agreement, at any time after the six month anniversary of the Closing, each holder of Post-Merger indie Units will be entitled to exchange such units for Class A common stock of the Company on a one-for-one basis (subject to customary conversion rate adjustments, including for stock splits, stock dividends and reclassifications). Based on the assumptions set forth under the section entitled “Frequently Used Terms — Share Calculations and Ownership Percentages,” the total number of Post-Merger indie Units issuable to the indie Equity Holders will be up to 40,243,644, entitling such members collectively to exchange them for 27.2% of the Company’s Class A common stock in the aggregate.

Pursuant to a Tax Receivable Agreement between the Company and certain indie Equity Holders, the Company will pay to such holders 85% of the tax savings that the Company realizes as a result of increases in tax basis in indie’s assets as a result of the exchange of the Post-Merger indie Units for shares of Class A common stock and certain tax attributes of the ADK Blocker Group and tax benefits related to entering into the Tax Receivable Agreement, including tax benefits attributable to payments under the Tax Receivable Agreement. For more information on the Tax Receivable Agreement, please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Tax Receivable Agreement.”

Additionally, in connection with the Mergers, the Company will issue to the ADK Principal Owners 34,021,833 shares of Class V common stock of the Company, in the aggregate. The Class V common stock provides no economic rights in the Company to the Class V Holders; however, each Class V Holder will be entitled to vote as a common stockholder of the Company, with one vote per share of Class V common stock of the Company. If, at any time, a Class V Holder exchanges any Post-Merger indie Units for Class A common stock of the Company pursuant to the Exchange Agreement, an equivalent number of such holder’s share of Class V common stock will automatically be canceled.

In connection with the Business Combination, the Sponsor has agreed pursuant to the Sponsor Letter Agreement, to hold 3,450,000 of its shares of Class B common stock in the Company in escrow subject to forfeiture if the Company does not satisfy the same stock-price based performance thresholds to which the Earn-Out Shares are subject. For more information on the Sponsor Letter Agreement, please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Sponsor Letter Agreement.”

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Q. How much consideration will the indie Equity Holders receive in connection with the acquisition of indie by Thunder Bridge II?

A. Pursuant to the MTA, the indie Equity Holders and holders of Phantom Equity Units will collectively be entitled to receive consideration (the “Merger Consideration”) in an amount equal to $900 million, which is subject to adjustment downward to the extent that the Target Companies’ indebtedness exceeds the Target Companies’ cash and cash equivalents at Closing. For more information on the adjustments to the Merger Consideration, see the section entitled “Shareholder Proposal 2: The Merger Proposal — The MTA — Merger Consideration.”

After the Closing, the indie Equity Holders at Closing will also have a contingent earn-out right to receive up to an additional 10,000,000 shares of Class A common stock of the Company (or additional Post-Merger indie Units exchangeable into Class A common stock pursuant to the Exchange Agreement, collectively referred to as the “Earn-Out Shares,” subject to the occurrence of certain stock price performance thresholds of the Company by December 31, 2027.

In connection with the Business Combination, the Sponsor has agreed pursuant to the Sponsor Letter Agreement, to hold 3,450,000 of its shares of Class B common stock in the Company in an escrow account with Continental Stock Transfer & Trust Company, as escrow agent, subject to forfeiture if the Company does not satisfy the same stock-price based performance thresholds to which the Earn-Out Shares are subject. For more information on the Earn-Out Shares, see “Shareholder Proposal 2: The Merger Proposal — The MTA — Earn Out Shares.”

Q. What is the Tax Receivable Agreement?

A. In connection with the Business Combination, the Company will enter into the Tax Receivable Agreement with certain Post-Merger indie Unit holders. Pursuant to the Tax Receivable Agreement, the Company will pay to such holders 85% of certain tax savings that the Company realizes due to increases in the tax basis in indie’s assets as a result of the exchange of such Post-Merger indie Units for shares of Class A common stock and certain tax attributes of the ADK Blocker Group and tax benefits related to entering into the Tax Receivable Agreement, including tax benefits attributable to payments under the Tax Receivable Agreement. For more information on the Tax Receivable Agreement, please see the section entitled “Shareholder Proposal 2: The Merger Proposal — Related Agreements — Tax Receivable Agreement.”

Q. What equity stake will current Thunder Bridge II shareholders and indie Equity Holders hold in the Company immediately after the completion of the Business Combination?

A. Upon the completion of the Business Combination (assuming, among other things, that no Thunder Bridge II shareholders exercise Redemption Rights with respect to their ordinary shares upon completion of the Business Combination and the other assumptions described under the section entitled “Frequently Used Terms — Share Calculations and Ownership Percentages”), Public Shareholders will own approximately 23.3% of the outstanding shares of the Company, the Sponsor will own approximately 5.8% of the outstanding shares of the Company, indie’s existing security holders will own approximately 60.8% of the outstanding shares of the Company (on an as-exchanged basis) and approximately 10.1% of the outstanding shares of the Company will be held by the PIPE Investors.

If any of the Public Shareholders exercise their Redemption Rights, the percentage of the Company’s outstanding common stock held by the current holders of Thunder Bridge II ordinary shares will decrease and the percentages of the Company’s outstanding common stock held by the indie Equity Holders will increase, in each case relative to the percentage held if none of the Thunder Bridge II ordinary shares are redeemed.

All of the relative percentages above are for illustrative purposes only and are based upon certain assumptions as described in the section entitled “Frequently Used Terms — Share Calculations and Ownership Percentages.” Should one or more of the assumptions prove incorrect, actual beneficial ownership percentages may vary materially from those described in this proxy statement/prospectus as anticipated, believed, estimated, expected or intended.

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Q. Did the Thunder Bridge II Board obtain a third-party valuation or fairness opinion in determining whether or not to proceed with the Business Combination?

A. No. The Thunder Bridge II Board did not obtain a third-party valuation or fairness opinion in connection with its determination to approve the Business Combination. Thunder Bridge II’s officers and directors have substantial experience in evaluating the operating and financial merits of companies from a wide range of industries and concluded that their experience and backgrounds, together with the experience and sector expertise of Thunder Bridge II’s advisors, enabled them to make the necessary analyses and determinations regarding the Business Combination. Accordingly, Thunder Bridge II shareholders will be relying solely on the judgment of the Thunder Bridge II Board in valuing indie’s business and assuming the risk that the Thunder Bridge II Board may not have properly valued such business.

Q. What happens to the funds deposited in the Trust Account after completion of the Business Combination?

A. After completion of the Business Combination, the funds in the Trust Account will be used to pay holders of the Public Shares who exercise Redemption Rights and, after paying the Redemptions, a portion will be used to pay transaction expenses incurred in connection with the Business Combination, including deferred IPO underwriting fees to Thunder Bridge II’s investment bankers and for working capital and general corporate purposes of the Company and its subsidiaries. Such funds may also be used to reduce the indebtedness and certain other liabilities of the Company and its subsidiaries. As of December 31, 2020, there were cash and marketable securities held in the Trust Account of approximately $349.6 million. These funds will not be released until the earlier of the completion of the Business Combination or the Redemption of the Public Shares if Thunder Bridge II is unable to complete a Business Combination by August 13, 2021 (except that interest earned on the amounts held in the Trust Account may be released earlier as necessary to pay for any franchise or income taxes and up to $100,000 in liquidation expenses). Thunder Bridge II estimates that it has incurred approximately $570,000 in out-of-pocket expenses directly attributable to performing due diligence on acquisition targets and negotiating the Business Combination, which will be borne by Thunder Bridge II and not its Sponsor, officers or directors.

Q. What happens if a substantial number of Public Shareholders vote in favor of the Merger Proposal and exercise their Redemption Rights?

A. Public Shareholders may vote in favor of the Business Combination and still exercise their Redemption Rights, provided that Thunder Bridge II (without regard to any assets or liabilities of the Target Companies) after payment of all such Redemptions, has at least $5,000,001 in net tangible assets immediately prior to the Closing. The Business Combination may be completed even though the funds available from the Trust Account and the number of Public Shareholders are substantially reduced as a result of Redemptions by Public Shareholders. It is a condition to indie’s obligations to close the transactions under the MTA that cash equal to at least $250 million (after expenses) be available after the Business Combination from funds in the Trust Account and the PIPE Financing, and that no more than 25% of the Trust Account shall be paid to redeeming shareholders, and that at least $75,000,000 is raised in the PIPE Financing. Such conditions to indie’s obligations to close may be waived by indie in its sole discretion. If the Business Combination is completed notwithstanding Redemptions, the Company will have fewer Public Shares and Public Shareholders, the trading market for the Company’s securities may be less liquid and the Company may not be able to meet the minimum listing standards for a national securities exchange. Furthermore, the funds available from the Trust Account for working capital purposes of the Company after the Business Combination may not be sufficient for its future operations and may not allow the Company to reduce indie’s indebtedness and/or pursue its strategy for growth.

Q. What conditions must be satisfied to complete the Business Combination?

A. Unless waived by the parties to the MTA, and subject to applicable law, the completion of the Business Combination is subject to a number of conditions set forth in the MTA, including, among others, with respect to the obligations of all of the parties to the MTA:

• termination or expiration of the waiting period under the HSR Act,

• approval by Thunder Bridge II’s shareholders of the Domestication Proposal, the Merger Proposal, the Director Election Proposal and the Nasdaq Proposal,

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• approval by the indie Equity Holders of the Business Combination,

• the contribution of certain holders of Class B Units of indie of their Class B Units to ADK Service Provider Holdco, in exchange for interests in ADK Service Provider Holdco,

• the effectiveness of the registration statement (of which this proxy statement/prospectus forms a part), and

With respect to the obligations of indie, among others:

• the accuracy of representations, warranties and covenants,

• Thunder Bridge II having delivered the Merger Consideration to indie,

• after giving effect to the completion of the Closing, the Company having no indebtedness,

• upon the completion of the Closing, no person or group (excluding any indie Equity Holder, the Sponsor or any PIPE Investor) owning in excess of 9.9% of the issued and outstanding shares of Company common stock, and no three persons or groups (excluding any indie Equity Holder, the Sponsor or any PIPE Investor) owning in the aggregate in excess of 25% of the issued and outstanding shares of Company common stock,

• the existing directors of Thunder Bridge II having resigned and the nine directors set forth in the MTA (or their replacements) having been appointed or elected to the Company Board in accordance with the DGCL,

• the completion of the Domestication simultaneously with the Business Combination,

• after giving effect to the Redemptions, there being at least $262,185,126 remaining in the Trust Account, before expenses,

• the PIPE Financing shall have raised at least $75,000,000,

• after giving effect to any Redemptions and the PIPE Financing, Surviving Pubco has at least $250,000,000 in cash and cash equivalents after expenses, and

• the Sponsor shall have delivered 3,450,000 shares of its Class B common stock into an escrow account with Continental Stock Transfer & Trust, as escrow agent, to be held subject to the earnout conditions described herein.

For a summary of the conditions that must be satisfied or waived prior to completion of the Business Combination, see the section entitled, “Shareholder Proposal 2: The Merger Proposal — The MTA — Closing Conditions.”

Q. When do you expect the Business Combination to be completed?

A. It is currently anticipated that the Business Combination will be completed in Spring 2021. This timing depends, among other things, on the approval of the Shareholder Proposals to be presented at the Shareholders Meeting. However, such meeting could be adjourned if the Shareholder Adjournment Proposal is adopted at the Shareholders Meeting, and Thunder Bridge II elects to adjourn the Shareholders Meeting to a later date or dates to permit further solicitation and vote of proxies if reasonably determined to be necessary or desirable by Thunder Bridge II.

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Q. Will Thunder Bridge II enter into any equity financing arrangements in connection with the Business Combination?

A. Yes. On December 14, 2020, Thunder Bridge II entered into the Subscription Agreements with certain investors for the PIPE Financing, pursuant to which Thunder Bridge II agreed to issue and sell to the PIPE Investors $150 million of Thunder Bridge II’s Class A ordinary shares, at a price of $10.00 per Class A ordinary share, simultaneously with or immediately prior to the Closing. The PIPE Financing is conditioned on the Closing being scheduled to occur concurrently with or immediately following the closing of the PIPE Financing and other customary closing conditions. Such shares, if unrestricted and freely tradable, would have an aggregate market value of approximately $151.8 million based on the last sale price of $10.12 per share on Nasdaq on May 10, 2021.

Despite the PIPE Financing, Thunder Bridge II may not be able to complete the Business Combination under the terms of the MTA in the event that too many of its Public Shareholders exercise their Redemption Rights and Thunder Bridge II cannot satisfy the conditions to closing set forth above (unless indie waives such requirements). Thunder Bridge II may determine prior to the Closing that it wants to seek additional equity financing in order to ensure that it has sufficient cash at the Closing, although indie has consent rights under the MTA with respect to any additional equity financing.

Q. Why is Thunder Bridge II proposing the Equity Incentive Plan Proposal?

A. The purpose of the 2021 Equity Incentive Plan is to enable the Company to offer eligible employees, directors and consultants cash and stock-based incentive awards in order to attract, retain and reward these individuals and strengthen the mutuality of interests between them and the Company’s stockholders. For more information, see the section entitled “Shareholder Proposal 3: The Equity Incentive Plan Proposal.”

Q. Why is Thunder Bridge II proposing the Director Election Proposal?

A. The MTA requires that the initial Company Board following the completion of the Business Combination be comprised of nine individuals, consisting of five individuals selected by indie, three individuals selected by Thunder Bridge II, and one individual mutually agreed upon by indie and Thunder Bridge II. To this end, the parties have selected Sonalee Parekh, Ichiro Aoki and Jeffrey Owens to serve as Class I directors for a term expiring at the Company’s 2022 annual meeting of stockholders, William Woodward, Karl-Thomas Neumann and Diane Brink to serve as Class II directors for a term expiring at the Company’s 2023 annual meeting of stockholders and Donald McClymont, Peter Kight and David Aldrich to serve as Class III directors for a term expiring at the Company’s 2024 annual meeting of stockholders. The Director Election Proposal is being presented to implement the requirement of the MTA to install the Company Board. See the section entitled “Shareholder Proposal 4: The Director Election Proposal” for additional information.

Q. Why is Thunder Bridge II proposing the Nasdaq Proposal?

A. Thunder Bridge II is proposing the Nasdaq Proposal in order to comply with the Nasdaq Listing Rules. Under Nasdaq Listing Rule 5635(a), shareholder approval is required prior to the issuance of securities in connection with the acquisition of another company if such securities are not issued in a public offering and (A) have, or will have upon issuance, voting power equal to or in excess of 20% of the voting power outstanding before the issuance of common stock (or securities convertible into or exercisable for common stock); or (B) the number of shares of common stock to be issued is or will be equal to or in excess of 20% of the number of shares of common stock outstanding before the issuance of the stock or securities. Under Nasdaq Listing Rule 5635(b), shareholder approval is required prior to the issuance of securities when the issuance or potential issuance will result in a change of control. Under Nasdaq Listing Rule 5635(d), shareholder approval is required for a transaction other than a public offering involving the sale, issuance or potential issuance by any issuer of common stock (or securities convertible into or exercisable for common stock) at a price less than the closing price of the stock if the number of equity securities to be issued is or may be equal to 20% or more of the common stock or 20% or more of the voting power outstanding before the issuance. For more information, see the section entitled “Shareholder Proposal 5: The Nasdaq Proposal.”

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Q. Why is Thunder Bridge II proposing the Advisory Charter Proposals?

A. Thunder Bridge II is asking its stockholders to vote upon, on a non-binding advisory basis, proposals to approve certain governance provisions contained in the proposed charter. These proposals are being presented in accordance with SEC guidance and will be voted upon on an advisory basis, and are not binding on Surviving Pubco, Thunder Bridge II or our Board (separate and apart from the approval of the Domestication Proposal and the Merger Proposal). By presenting these proposals separately, we intend to provide stockholders a means to communicate their separate views on important governance provisions to the Board. In the judgment of the Board, these provisions are necessary to adequately address the needs of the combined company. Please see the section entitled “Shareholder Proposal 6: The Advisory Charter Proposals” for additional information.

Q. Why is Thunder Bridge II proposing the Shareholder Adjournment Proposal?

A. Thunder Bridge II is proposing the Shareholder Adjournment Proposal to allow the adjournment of the Shareholders Meeting to a later date or dates, including if necessary to permit further solicitation and vote of proxies if it is determined by Thunder Bridge II that more time is necessary or appropriate to approve one or more of the Shareholder Proposals at the Shareholders Meeting. Please see the section entitled “Shareholder Proposal 7: The Shareholder Adjournment Proposal” for additional information.

Q. When and where will the Shareholders Meeting be held?

A. The Shareholders Meeting will be held at 11:00 a.m. Eastern Time on June 9, 2021 at 101 Constitution Ave., NW, Suite 900, Washington, DC 20001, USA and via live webcast at https://www.cstproxy.com/thunderbridgeacquisitionii/sm2021. Only shareholders who held ordinary shares of Thunder Bridge II at the close of business on May 10, 2021 will be entitled to vote at the Shareholders Meeting and at any adjournments thereof.

As a registered shareholder, you received a proxy card from the Transfer Agent, which contains instructions on how to attend the Shareholders Meeting in person online, including the URL address, along with your 12-digit meeting control number. You will need the 12-digit meeting control number that is printed on your proxy card to enter the Shareholders Meeting. If you do not have your 12-digit meeting control number, contact the Transfer Agent at (917) 262-2373 or e-mail the Transfer Agent at proxy@continentalstock.com.

You can pre-register to attend the Shareholders Meeting in person online starting , 2021. Enter the URL address into your browser, and enter your 12-digit meeting control number, name and email address. Once you pre-register you can vote or enter questions in the chat box. Prior to or at the start of the Shareholders Meeting you will need to re-log in using your 12-digit meeting control number and will also be prompted to enter your 12-digit meeting control number if you vote in person online during the Shareholders Meeting. Thunder Bridge II recommends that you log in at least 15 minutes before the Shareholders Meeting to ensure you are logged in when the special meeting starts.

If your shares are held in “street name,” you may attend the Shareholders Meeting. You will need to contact the Transfer Agent at the number or email address above, to receive a 12-digit meeting control number and gain access to the Shareholders Meeting or otherwise contact your broker, bank, or other nominee as soon as possible, to do so. Please allow up to 72 hours prior to the special meeting for processing your 12-digit meeting control number.

Q. Who is entitled to vote at the Shareholders Meeting?

A. Thunder Bridge II has fixed May 10, 2021 as the Record Date. If you were a shareholder of Thunder Bridge II at the close of business on the Record Date, you are entitled to vote on matters that come before the Shareholders Meeting except that only holders of Founder Shares as of the Record Date are entitled to vote on the Director Election Proposal.

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Q. How do I vote?

A. If you are a record owner of your shares, there are two ways to vote your Thunder Bridge II Shares at the Shareholders Meeting:

You Can Vote By Signing and Returning the Enclosed Proxy Card. If you vote by proxy card, your “proxy,” whose name is listed on the proxy card, will vote your shares and/or your warrants as you instruct on the proxy card. If you sign and return the proxy card but do not give instructions on how to vote your shares, your shares will be voted as recommended by the Thunder Bridge II Board “FOR” the Domestication Proposal, the Merger Proposal, the Equity Incentive Plan Proposal, the Nasdaq Proposal, and the Shareholder Adjournment Proposal (if presented). Only holders of Thunder Bridge II’s Class B ordinary shares may vote for the election of each of the directors pursuant to The Director Election Proposal

You Can Attend the Shareholders Meeting and Vote via Live Webcast. If you choose to participate in the Shareholders Meeting, you can vote your shares electronically during the Shareholders Meeting via live webcast by visiting https://www.cstproxy.com/thunderbridgeacquisitionii/sm2021. You will need the 12-digit meeting control number that is printed on your proxy card to enter the Shareholders Meeting. Thunder Bridge II recommends that you log in at least 15 minutes before the Shareholders Meeting to ensure you are logged in when the Shareholders Meeting starts.

If your shares are held in “street name” or are in a margin or similar account, you should contact your broker to ensure that votes related to the shares you beneficially own are properly counted. If you wish to attend the Shareholders Meeting and vote in person via the live webcast and your shares are held in “street name,” you must obtain a legal proxy from your broker, bank or nominee. That is the only way Thunder Bridge II can be sure that the broker, bank or nominee has not already voted your shares.

Q: What if I do not vote my Thunder Bridge II Shares or if I abstain from voting?

A: If you abstain from voting on the Shareholder Proposals, your Thunder Bridge II Shares will be counted as present for purposes of establishing a quorum (if so present in accordance with the terms of the Memorandum and Articles of Association), but the abstention will have no effect on the outcome of such proposal.

Q: What Shareholder Proposals must be passed in order for the Business Combination to be completed?

A: The Business Combination will not be completed unless the Domestication Proposal, the Merger Proposal, the Director Election Proposal, and the Nasdaq Proposal, are approved. If Thunder Bridge II does not complete a Business Combination by August 13, 2021, Thunder Bridge II will be required to dissolve and liquidate itself and return the monies held within its Trust Account to its Public Shareholders unless Thunder Bridge II submits and its shareholders approve an extension.

Q: How does the Thunder Bridge II Board recommend that I vote on the Shareholder Proposals?

A: The Thunder Bridge II Board unanimously recommends that the holders of Thunder Bridge II’s ordinary shares entitled to vote on the Shareholder Proposals, vote as follows:

“FOR” approval of the Domestication Proposal;

“FOR” approval of the Merger Proposal;

“FOR” approval of the Equity Incentive Plan Proposal;

“FOR” approval of the election of each of the director nominees pursuant to the Director Election Proposal;

“FOR” approval of the Nasdaq Proposal;

“FOR” approval of the Advisory Charter Proposals; and

“FOR” approval of the Shareholder Adjournment Proposal, if presented.

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Q: How many votes do I have?

A: Thunder Bridge II shareholders have one vote per each ordinary share of Thunder Bridge II held by them on the Record Date for each of the Shareholder Proposals to be voted upon.

Q: What will happen if I return my proxy card without indicating how to vote?

A: If you sign and return your proxy card without indicating how to vote on any particular Shareholder Proposal, the ordinary shares represented by your proxy will be voted in favor of each Shareholder Proposal. Proxy cards that are returned without a signature will not be counted as present at the Shareholder Meeting and cannot be voted.

Q. How will the Sponsor and Thunder Bridge II’s officers and directors vote in connection with the Shareholder Proposals?

A. As of the Record Date, the Sponsor owned of record an aggregate of 8,625,000 Founder Shares, representing 20% of the issued and outstanding Thunder Bridge II Shares. Pursuant to the Sponsor Support Letter and the Insider Letter Agreement, the Sponsor and Thunder Bridge II’s directors and officers have agreed to vote the ordinary shares owned by them (including the Founder Shares) in favor of the Shareholder Proposals. The Sponsor and Thunder Bridge II’s officers and directors, as of the Record Date, have not acquired any Thunder Bridge II ordinary shares during or after our IPO in the open market. However, any subsequent purchases of Thunder Bridge II ordinary shares prior to the Record Date by the Sponsor or Thunder Bridge II’s officers and directors in the aftermarket will make it more likely that the Shareholder Proposals will be approved as such shares would be voted in favor of the Shareholder Proposals. As of the Record Date, there were 43,125,000 ordinary shares of Thunder Bridge II outstanding.

Q. Do the Sponsor and Thunder Bridge II’s officers and directors have any conflicts of interests that may influence them to support the Business Combination?

A. Thunder Bridge II’s Sponsor owns 8,625,000 Class B ordinary shares, which were initially acquired prior to the IPO for an aggregate purchase price of $25,000 and Thunder Bridge II’s directors and officers have pecuniary interests in such ordinary shares through their ownership interest in the Sponsor. Such shares had an aggregate market value of approximately $87.3 million based on the last sale price of $10.12 per share on Nasdaq on May 10, 2021. In addition, the Sponsor purchased an aggregate of 8,650,000 Private Placement Warrants, each exercisable for one Class A ordinary share of Thunder Bridge II at $11.50 per share, for a purchase price of $8,650,000, or $1.00 per warrant. Such warrants had an aggregate market value of approximately $14.7 million based on the last sale price of $1.81 per warrant on Nasdaq on May 10, 2021. The Memorandum and Articles of Association require Thunder Bridge II to complete an initial business combination prior to August 13, 2021 (unless Thunder Bridge II submits and its shareholders approve an extension of such date). If the Business Combination is not completed and Thunder Bridge II is forced to wind up, dissolve and liquidate in accordance with the Memorandum and Articles of Association, the 8,625,000 ordinary shares currently held by Thunder Bridge II’s Sponsor and the Private Placement Warrants purchased by Sponsor will be worthless (as the holders have waived liquidation rights with respect to such ordinary shares).

Certain officers and directors of Thunder Bridge II also participate in arrangements that may be argued to provide them with other interests in the Business Combination that are different from yours, including, among others, arrangements for the continued service as directors of the Company.

These interests, among others, may influence or have influenced the Sponsor and the officers and directors of Thunder Bridge II and indie to support or approve the Business Combination. See “Risk Factors — Risks Related to the Domestication and the Business Combination — Some of Thunder Bridge II’s officers and directors may have conflicts of interest that may influence or have influenced them to support or approve the Business Combination without regard to your interests or in determining whether indie is appropriate for Thunder Bridge II’s initial business combination.”

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Q. Do I have Redemption Rights with respect to my Thunder Bridge II Shares?

A. Under Section 49.2 of the Memorandum and Articles of Association, prior to the completion of the Business Combination, Thunder Bridge II will provide all of the Public Shareholders with the opportunity to have their shares redeemed upon the completion of the Business Combination, subject to certain limitations, for cash equal to the applicable Redemption Price; provided, however, that Thunder Bridge II may not redeem such shares to the extent that such Redemption would result in Thunder Bridge II having net tangible assets (as determined under the Exchange Act) of less than $5,000,001 upon the completion of the Business Combination.

Q: May the Sponsor, Thunder Bridge II’s directors, officers, advisors or their affiliates purchase shares in connection with the Business Combination?

A: The Sponsor and Thunder Bridge II’s directors, officers, advisors or their affiliates may purchase Thunder Bridge II Shares in privately negotiated transactions or in the open market either prior to or after the Closing of the Business Combination, including from Thunder Bridge II shareholders who would have otherwise exercised their Redemption Rights. However, the Sponsor, directors and officers have no current commitments or plans to engage in such transactions and have not formulated any terms or conditions for any such transactions at the date of this proxy statement/prospectus. If Thunder Bridge II engages in such transactions, any such purchases will be subject to limitations regarding possession of any material nonpublic information not disclosed to the seller of such shares and they will not make any such purchases if such purchases are prohibited by Regulation M under the Exchange Act. Any such purchase after the Record Date would include a contractual acknowledgement that the selling shareholder, although still the record holder of Thunder Bridge II Shares, is no longer the beneficial owner thereof and therefore agrees not to exercise its Redemption Rights. In the event the Sponsor or Thunder Bridge II’s directors, officers or advisors or their 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 in excess of the per-share pro rata portion of the aggregate amount then on deposit in the Trust Account.

Pursuant to the Insider Letter Agreement, the Sponsor and Thunder Bridge II’s directors and officers have agreed to waive their Redemption Rights with respect to (i) the 8,625,000 Founder Shares owned by the Sponsor and (ii) any other Thunder Bridge II ordinary shares owned by the Sponsor or Thunder Bridge II’s directors and officers, and such shares will be excluded from the pro rata calculation used to determine the per-share Redemption Price. However, if the Sponsor or Thunder Bridge II’s directors, officers and their affiliates acquired Public Shares in or after the IPO (or acquire Public Shares following the date of this proxy statement/prospectus), they will be entitled to liquidating distributions from the Trust Account with respect to such Public Shares if Thunder Bridge II fails to complete a Business Combination by August 13, 2021.

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Q. Is there a limit on the number of shares I may redeem?

A. Each Public Shareholder, together with any affiliate or any other person with whom such Public Shareholder 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 15% or more of the Public Shares. Accordingly, any shares held by a Public Shareholder or “group” in excess of such 15% cap will not be redeemed by Thunder Bridge II. Any Public Shareholder who holds less than 15% of the Public Shares may have all of the Public Shares held by him or her redeemed for cash.

Q. How do I exercise my Redemption Rights?

A. If you are a Public Shareholder and you seek to have your shares redeemed, you must (i) demand, no later than 5:00 p.m., Eastern time on June 7, 2021 (two (2) business days before the Shareholders Meeting), that Thunder Bridge II redeem your shares for cash; (ii) affirmatively certify in your request to Thunder Bridge II’s Transfer Agent for Redemption if you “ARE” or “ARE NOT” acting in concert or as a “group” (as defined in Section 13d-3 of the Exchange Act) with any other Public Shareholders and (iii) submit your request in writing to the Transfer Agent, at the address listed at the end of this section and deliver your shares to the Transfer Agent physically or electronically using The Depository Trust Company’s DWAC system at least two business days prior to the vote at the Shareholders Meeting.

Any request for Redemption, once made by a Public Shareholder, may be withdrawn at any time up to the time the vote is taken with respect to the Merger Proposal at the Shareholders Meeting. In addition, if you deliver your shares for Redemption to Thunder Bridge II’s Transfer Agent and later decide prior to the Shareholders Meeting not to elect Redemption, you may request that Thunder Bridge II’s Transfer Agent return the shares (physically or electronically). You may make such request by contacting Thunder Bridge II’s Transfer Agent at the phone number or address listed at the end of this section.

Any corrected or changed written demand of Redemption Rights must be received by Thunder Bridge II’s secretary two business days prior to the vote taken on the Merger Proposal at the Shareholders Meeting. No demand for Redemption will be honored unless the holder’s shares have been delivered (either physically or electronically) to the Transfer Agent at least two business days prior to the vote at the Shareholders Meeting.

Public Shareholders seeking to exercise their Redemption Rights and opting to deliver physical certificates should allot sufficient time to obtain physical certificates from the Transfer Agent and time to effect delivery. It is Thunder Bridge II’s understanding that shareholders should generally allot at least two weeks to obtain physical certificates from the Transfer Agent. However, Thunder Bridge II does not have any control over this process and it may take longer than two weeks. Public Shareholders who hold their shares in street name will have to coordinate with their banks, brokers or other nominees to have the shares certificated or delivered electronically. There is a nominal cost associated with this tendering process and the act of certificating the shares or delivering them through the DWAC system. The Transfer Agent will typically charge a nominal fee to the tendering broker and it would be up to the broker whether or not to pass this cost on to the redeeming shareholder. In the event the Business Combination is not completed, this may result in an additional cost to shareholders for the return of their shares.

If a Public Shareholder properly demands Redemption as described above, then, if the Business Combination is completed, Thunder Bridge II will redeem the shares subject to the Redemptions for cash. Such amount will be paid promptly after completion of the Business Combination. If you exercise your Redemption Rights, then you will be exchanging your Thunder Bridge II Shares for cash and will no longer own these shares following the Business Combination.

If you are a Public Shareholder and you exercise your Redemption Rights, it will not result in either the exercise or loss of any Thunder Bridge II warrants that you may hold. Your Thunder Bridge II warrants will continue to be outstanding following a Redemption of your Thunder Bridge II Shares and will become exercisable in connection with the completion of the Business Combination.

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If you intend to seek Redemption of your Public Shares, you will need to deliver your shares (either physically or electronically) to the Transfer Agent prior to the meeting, as described in this proxy statement/prospectus. If you have questions regarding the certification of your position or delivery of your shares, please contact:

Continental Stock Transfer & Trust Company
One State Street, 30th Floor
New York, New York 10004
Attention: Mark Zimkind
E-mail: mzimkind@continentalstock.com

Q. What happens if the Business Combination is not completed?

A. If a Public Shareholder has tendered shares to be redeemed but the Business Combination is not completed, the Redemptions will be canceled and the tendered shares will be returned to the relevant Public Shareholders as appropriate. The current deadline set forth in the Memorandum and Articles of Association for Thunder Bridge II to complete its initial Business Combination is August 13, 2021 (24 months after the closing of the IPO).

Q: What happens if I sell my shares before the Shareholders Meeting?

A: The Record Date for the Shareholders Meeting is earlier than the date of the Shareholders Meeting, as well as the date that the Business Combination is expected to be consummated. If you transfer your ordinary shares after the Record Date, but before the Shareholders Meeting, unless the transferee obtains from you a proxy to vote those shares, you would retain your right to vote at the Shareholders Meeting, but will transfer ownership of the shares and will not hold an interest in the Company after the Business Combination is consummated.

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SELECTED HISTORICAL FINANCIAL DATA OF THUNDER BRIDGE II

The following table sets forth selected historical financial data derived from Thunder Bridge II’s audited financial statements as of December 31, 2020 and 2019 and for the year ended December 31, 2020 and for the period from February 13, 2019 (inception) through December 31, 2019, each of which is included elsewhere in this proxy statement/prospectus. Such financial information should be read in conjunction with the audited financial statements and related notes included elsewhere in this proxy statement/prospectus.

The historical results presented below are not necessarily indicative of the results to be expected for any future period. You should carefully read the following selected financial information in conjunction with the section entitled “Management’s Discussion and Analysis of Financial Condition and Results of Operations of Thunder Bridge II” and Thunder Bridge II’s financial statements and the related notes appearing elsewhere in this proxy statement/prospectus.

	At or for the Year Ended December 31, 2020 (Restated)			At or for the Period from February 13, 2019 (Inception) to December 31, 2019 (Restated)
Statement of Operations Data:
Operating expenses
Formation costs and other operating expenses	$	1,620,837		$	379,352
Loss from operations		(1,620,837	)		(379,352	)
Other income
Interest and unrealized gains on marketable securities		2,122,286			2,460,851
Changes in fair value of warrant liability		(73,794,379	)		1,538,409
Net (loss) income	$	(73,292,930	)	$	3,619,908
Basic net loss per share attributable to ordinary shares	$	(8.74	)	$	0.14
Weighted average shares outstanding, basic and diluted		8,625,000			8,437,500

Cash Flow Data:
Net cash used in operating activities	$	(663,852	)	$	(768,913	)
Net cash used in investing activities		—			(345,000,000	)
Net cash provided by (used in) financing activities		300,000			346,266,462

Balance Sheet Data:
Cash	$	133,695		$	497,549
Cash and investments held in Trust Account		349,583,138			347,460,852
Total assets		349,776,163			348,389,695
Total liabilities		110,183,544			35,504,147
Ordinary shares subject to possible redemption		349,583,138			347,460,852
Total shareholders’ equity (deficit)		(109,990,519	)		(34,575,303	)

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SELECTED HISTORICAL CONSOLIDATED FINANCIAL AND OTHER DATA OF INDIE

The selected historical consolidated statements of operations data of indie for the years ended December 31, 2020 and 2019 and the historical consolidated balance sheet data as of December 31, 2020 and 2019 are derived from indie’s audited consolidated financial statements included elsewhere in this prospectus/proxy statement. You should read the following selected historical consolidated financial data together with “Management’s Discussion and Analysis of Financial Condition and Results of Operations of indie” and indie’s consolidated financial statements and related notes included elsewhere in this prospectus/proxy statement.

	Year Ended December 31,
	2020			2019
	(in thousands, except unit and per unit data)
Statement of Operations Data:
Revenue:
Product revenue	$	19,488		$	20,814
Contract revenue		3,122			1,898
Total revenue		22,610			22,712
Operating expenses:
Cost of goods sold		13,042			15,717
Research and development		22,013			20,186
Selling, general, and administrative		6,796			5,719
Total operating expenses		41,851			41,622
Loss from operations		(19,241	)		(18,910	)
Other income (expense), net:
Interest income		25			180
Interest (expense)		(2,193	)		(2,215	)
Other income (expense), net		(76,926	)		16
Total other income (expense), net		(79,094	)		(2,019	)
Net loss before income taxes		(98,335	)		(20,929	)
Income tax expense		29			11
Net loss		(98,364	)		(20,940	)
Less: Net loss attributable to non-controlling interest		(866	)		(486	)
Net loss attributable to Ay Dee Kay, LLC	$	(97,498	)	$	(20,454	)

Net loss per unit attributable to common unitholders – basic and diluted(1)	$	(86.68	)	$	(18.59	)

Weighted average common units outstanding – basic and diluted		1,124,864			1,100,423

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(1) See indie’s audited consolidated financial statements and related notes included elsewhere in this proxy statement/prospectus for an explanation of the calculations of our net loss per unit attributable to common unitholders, basic and diluted.

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	Year Ended December 31,
	2020			2019
	(in thousands)
Cash Flow Data:
Net cash used in operating activities	$	(21,218	)	$	(14,875	)
Net cash used in investing activities		(771	)		(2,200	)
Net cash provided by (used in) financing activities		33,474			125

	As of December 31,
	2020			2019
	(in thousands)
Consolidated Balance Sheet Data:
Cash and cash equivalents	$	18,698		$	7,155
Working capital		(92,223	)		823
Total assets		35,126			21,373
Long-term debt, net of current portion		12,345			11,416
Convertible debt, net of current portion		—			3,375
Total members’ deficit		(101,492	)		(10,582	)

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SELECTED UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL DATA

The following selected unaudited pro forma condensed combined financial data is derived from the unaudited pro forma condensed combined balance sheet and unaudited pro forma condensed combined statement of operations included elsewhere in this proxy statement/prospectus.

The unaudited pro forma condensed combined financial statements are based on Thunder Bridge II’s historical financial statements and indie’s historical consolidated financial statements as adjusted to give effect to the Business Combination, the PIPE Financing, and the issuance of a simple agreement for future equity (SAFE) in the second quarter of 2021 (the “Additional SAFE Agreement”). The unaudited pro forma condensed combined balance sheet gives pro forma effect to the Business Combination, treated as a reverse recapitalization for accounting purposes, the PIPE Financing, and the Additional SAFE Agreement as if they had been consummated on December 31, 2020. The unaudited pro forma condensed combined statement of operations for the year ended December 31, 2020, gives effect to the Business Combination, the PIPE Financing, and the Additional SAFE Agreement as if they had occurred on January 1, 2020.

The unaudited pro forma condensed combined financial statements were prepared in accordance with Article 11 of SEC Regulation S-X, as amended by the final rule, Release No. 33-10786 “Amendments to Financial Disclosures about Acquired and Disposed Businesses.” Release No. 33-10786 replaces the existing pro forma adjustment criteria with simplified requirements to depict the accounting for the transaction (“Transaction Accounting Adjustments”) and present the reasonably estimable synergies and other transaction effects that have occurred or reasonably expected to occur (“Management’s Adjustments”). Thunder Bridge II has elected not to present Management’s Adjustments and will only be presenting Transaction Accounting Adjustments in the unaudited pro forma condensed combined financial information. The adjustments presented in the unaudited pro forma condensed combined financial statements have been identified and presented to provide relevant information necessary for an understanding of the combined company upon consummation of the Business Combination, the PIPE Financing, and the Additional SAFE Agreement.

The unaudited pro forma condensed combined financial information is for illustrative purposes only. The financial results may have been different had the companies always been combined. You should not rely on the unaudited pro forma condensed combined financial information as being indicative of the historical results that would have been achieved had the companies always been combined or the future results that the combined company will experience. Thunder Bridge II and indie have not had any historical relationship prior to the Business Combination. Accordingly, no pro forma adjustments were required to eliminate activities between the companies.

This information should be read together with Thunder Bridge II’s and indie’s historical financial statements and related notes, “Unaudited Pro Forma Condensed Combined Financial Information,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations of Thunder Bridge II,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations of indie,” and other financial information relating to Thunder Bridge II and indie included elsewhere in this proxy statement/prospectus.

The selected unaudited pro forma condensed combined financial data below presents two redemption scenarios as follows: