UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (date of earliest event reported): June 4, 2021

GigCapital4, Inc.

(Exact name of registrant as specified in its charter)

1731 Embarcadero Rd., Suite 200

Palo Alto, CA 94303

(650) 276-7040

(Registrant’s Telephone Number, Including Area Code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instructions A.2. below):

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

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 13(a) of the Exchange Act.  ☐

Item 8.01 Other Events.

On June 4, 2021, GigCapital4, Inc., a Delaware corporation (“GigCapital4”), entered into an Agreement and Plan of Merger (the “Merger Agreement”) with GigCapital4 Merger Sub Corporation, a Delaware corporation and direct, wholly owned subsidiary of GigCapital4 (“Merger Sub”), BigBear.ai Holdings, LLC, a Delaware limited liability company (the “Target”), and BBAI Ultimate Holdings, LLC, a Delaware limited liability company (“Holdings”).

On June 4, 2021, GigCapital4 issued a press release announcing the execution of the Merger Agreement and made available on its website an investor presentation that contains information which was used by GigCapital4 in connection with the agreed sale of GigCapital4 convertible notes to certain investors. The press release and the investor presentation are filed herewith as Exhibits 99.1 and 99.2, respectively, and both are incorporated by reference herein.

The submission of the information set forth in this Item 8.01 shall not be deemed an admission as to the materiality of any information in this Item 8.01, including the information presented in Exhibit 99.1 and Exhibit 99.2.

Additional Information

The proposed transactions will be submitted to stockholders of GigCapital4 for their consideration and approval at a special meeting of stockholders. In connection with the proposed transactions, GigCapital4 intends to file a definitive proxy statement (the “Proxy Statement”) with the Securities and Exchange Commission (“SEC”) to be distributed to GigCapital4’s stockholders in connection with GigCapital4’s solicitation for proxies for the vote by GigCapital4’s stockholders in connection with the proposed transactions and other matters as described in such Proxy Statement. After the Proxy Statement has been filed and declared effective, GigCapital4 will mail the Proxy Statement and other relevant documents to its stockholders as of the record date established for voting on the proposed transactions. Investors and security holders of GigCapital4 are advised to read, when available, the preliminary Proxy Statement, and any amendments thereto, and the definitive Proxy Statement in connection with GigCapital4’s solicitation of proxies for its special meeting of stockholders to be held to approve the proposed transaction because the Proxy Statement will contain important information about the proposed transaction and the parties to the proposed transaction. Stockholders will also be able to obtain copies of the Proxy Statement, without charge, once available, at the SEC’s website at www.sec.gov.

This Current Report on Form 8-K does not constitute an offer to sell or the solicitation of an offer to buy any securities, or a solicitation of any vote or approval, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act of 1933, as amended.

INVESTMENT IN ANY SECURITIES DESCRIBED HEREIN HAS NOT BEEN APPROVED OR DISAPPROVED BY THE SEC OR ANY OTHER REGULATORY AUTHORITY NOR HAS ANY AUTHORITY PASSED UPON OR ENDORSED THE MERITS OF THE OFFERING OR THE ACCURACY OR ADEQUACY OF THE INFORMATION CONTAINED HEREIN. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

Participants in the Solicitation

GigCapital4 and Target and their respective directors, executive officers, other members of management, and employees, under SEC rules, may be deemed to be participants in the solicitation of proxies of GigCapital4’s stockholders in connection with the proposed transactions. Information regarding the persons who may, under SEC

rules, be deemed participants in the solicitation of GigCapital4’s stockholders in connection with the proposed transactions will be set forth in the Proxy Statement when it is filed with the SEC. Investors and security holders may obtain more detailed information regarding the names and interests in the proposed transactions of GigCapital4’s directors and officers in GigCapital4’s filings with the SEC, including GigCapital4’s final prospectus dated February 8, 2021 and Annual Report on Form 10-K for the fiscal year ended December 31, 2020, which was filed with the SEC on March 31, 2021, and such information will also be in the Proxy Statement to be filed with the SEC by GigCapital4 for the proposed transactions.

Forward-Looking Statements

Certain statements included in this Current Report on Form 8-K and the exhibits hereto that are not historical facts are forward-looking statements for purposes of the safe harbor provisions under the United States Private Securities Litigation Reform Act of 1995. Forward-looking statements generally are accompanied by words such as “believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “expect,” “should,” “would,” “plan,” “predict,” “potential,” “seem,” “seek,” “future,” “outlook,” and similar expressions that predict or indicate future events or trends or that are not statements of historical matters. These forward-looking statements include, but are not limited to, statements regarding GigCapital4’s and Target’s respective industries, future events, the proposed transactions between GigCapital4, Merger Sub, Target and the Holdings, the estimated or anticipated future results and benefits of the combined company following the proposed transactions, including the likelihood and ability of the parties to successfully consummate the proposed transactions, future opportunities for the combined company, and other statements that are not historical facts. These statements are based on various assumptions, whether or not identified herein, and on the current expectations of Target’s and GigCapital4’s management and are not predictions of actual performance. These forward-looking statements are provided for illustrative purposes only and are not intended to serve as, and must not be relied on by any investor as, a guarantee, an assurance, a prediction or a definitive statement of fact or probability. Actual events and circumstances are difficult or impossible to predict and will differ from assumptions. Many actual events and circumstances are beyond the control of Target and GigCapital4. These forward-looking statements are subject to a number of risks and uncertainties, including changes in domestic and foreign business, market, financial, political, and legal conditions; the inability of the parties to successfully or timely consummate the proposed transactions, including the risk that any required regulatory approvals are not obtained, are delayed or are subject to unanticipated conditions that could adversely affect the combined company or the expected benefits of the proposed transactions or that the approval of GigCapital4’s stockholders is not obtained; failure to realize the anticipated benefits of the proposed transactions; risks relating to the uncertainty of the projected financial information with respect to the Target; risks related to the rollout of the Target’s business and the timing of expected business milestones; the effects of competition on the Target’s future business; the amount of redemption requests made by GigCapital4’s public stockholders; the ability of GigCapital4 or the combined company to issue equity or equity-linked securities in connection with the proposed transactions or in the future, and those factors discussed in GigCapital4’s final prospectus dated February 8, 2021 and Annual Report on Form 10-K for the fiscal year ended December 31, 2020, in each case, under the heading “Risk Factors,” and other documents of GigCapital4 filed, or to be filed, with the SEC. If any of these risks materialize or our assumptions prove incorrect, actual results could differ materially from the results implied by these forward-looking statements. There may be additional risks that none of GigCapital4 or Target presently know or that GigCapital4 or Target currently believe are immaterial that could also cause actual results to differ from those contained in the forward-looking statements. In addition, forward-looking statements reflect GigCapital4’s and Target’s expectations, plans or forecasts of future events and views as of the date of this Current Report on Form 8-K. GigCapital4 and Target anticipate that subsequent events and developments will cause GigCapital4’s and Target’s assessments to change. However, while GigCapital4 and Target may elect to update these forward-looking statements at some point in the future, GigCapital4 and Target specifically disclaim any obligation to do so. These forward-looking statements should not be relied upon as representing GigCapital4’s and Target’s assessments as of any date subsequent to the date of this Current Report on Form 8-K. Accordingly, undue reliance should not be placed upon the forward-looking statements. Certain market data information in this Current Report on Form 8-K is based on the estimates of Target and GigCapital4 management. Target and GigCapital4 obtained the industry, market and competitive position data used throughout this Current Report on Form 8-K from internal estimates and research as well as from industry publications and research, surveys and studies conducted by third parties. Target and GigCapital4 believe their estimates to be accurate as of the date of this Current Report on Form 8-K. However, this information may prove to be inaccurate because of the method by which the Target or GigCapital4 obtained some of the data for its estimates or because this information cannot always be verified due to the limits on the availability and reliability of raw data, the voluntary nature of the data gathering process.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: June 4, 2021