☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF1934 For the quarterly period ended March 31, 2026OR ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF1934 For the transition period from ______ to __________Commission File Number: 001-43074 GigCapital9 Corp.(Exact Name of Registrant as Specified in its Charter) Cayman Islands98-1894186( State or other jurisdiction ofincorporation or organization)(I.R.S. EmployerIdentification No.)1731 Embarcadero Rd., Suite 200Palo Alto, CA94303(Address of principal executive offices)(Zip Code)Registrant’s telephone number, including area code: (650) 276-7040 Securities registered pursuant to Section 12(b) of the Act: Title of each classTradingSymbol(s)Name of each exchange on which registeredUnits, each consisting of one Class A ordinary share, $0.0001 parvalue, and one right to receive one-fifth of one Class A ordinaryshareGIXXUThe Nasdaq Stock Market LLCClass A ordinary shares, par value $0.0001 per shareGIXThe Nasdaq Stock Market LLCRights, to receive one-fifth of one Class A ordinary share.GIXXRThe Nasdaq Stock Market LLC Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities ExchangeAct of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has beensubject to such filing requirements for the past 90 days.Yes☒No☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant toRule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was requiredto submit such files).Yes☒No☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reportingcompany, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and“emerging growth company” in Rule 12b-2 of the Exchange Act. Large accelerated filer☐Non-accelerated filer☒Emerging growth company☒ Accelerated filer☐Smaller reporting company☒ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complyingwith any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).Yes☒No☐ As of May 13, 2026, the registrant had 25,688,954 Class A ordinary shares, $0.0001 par value per share and 10,857,857 Class B ordinaryshares, $0.0001 par value per share, issued and outstanding. Table of Contents PART I.FINANCIAL INFORMATION Item 1.Condensed Financial Statements (Unaudited)Condensed Balance SheetsCondensed Statement of Operations and Comprehensive IncomeCondensed Statement of Shareholders' Equity (Deficit)Condensed Statement of Cash FlowsNotes to Unaudited Condensed Financial StatementsItem 2.Management’s Discussion and Analysis of Financial Condition and Results of OperationsItem 3.Quantitative and Qualitative Disclosures About Market RiskItem 4.Controls and Procedures PART II.OTHER INFORMATION Item 1.Legal Proceedings19Item 1A.Risk Factors19Item 2.Unregistered Sales of Equity Securities and Use of Proceeds19Item 3.Defaults Upon Senior Securities20Item 4.Mine Safety Disclosures20Item 5.Other Information20Item 6.Exhibits20Signatures22 PART I—FINANCIAL INFORMATION GigCapital9 Corp.Condensed Balance Sheets(Unaudited) GigCapital9 Corp.Condensed Statement of Operations and Comprehensive Income(Unaudited) The accompanying notes are an integral part of these condensed financial statements. GigCapital9 Corp.Condensed Statement of Shareholders’ Equity (Deficit)(Unaudited) GigCapital9 Corp.Condensed Statement of Cash Flows(Unaudited) For the Three MonthsEndedMarch 31, 2026OPERATING ACTIVITIESNet income$1,252,174Adjustments to reconcile net income to net cash used by operating activities:Interest and dividends earned on cash and marketable securities held in Trust Account(1,531,176)Changes in operating liabilities:Prepaid expenses and other current assets(227,737)Other assets(52,450)Accounts payable79,154Related party payable20,371Accrued liabilities11,646Net cash used by operating activities(448,018)INVESTING ACTIVITIESInvestment of cash in Trust Account(253,000,000)Net cash used in investing activities(253,000,000)FINANCING ACTIVITIESProceeds from sale of public units, net of underwriting discount paid251,975,000Proceeds from sale of Private Investor Shares and Private Placement Units3,763,938Repayment of related party loan(2,626)Payment of offering costs(499,053)Net cash provided by financing activities255,237,259Net increase in cash1,789,241Cash at beginning of period73,881Cash at