GigCapital9 Corp.

Item 8.01 Other Events As previously disclosed by the Company in its Current Report on Form 8-K, as filed with the U.S. Securities and Exchange Commission (the “SEC”) on January 30, 2026 (the “IPO Closing 8-K”), the Company consummated its initial public offering (the “IPO”) on January 28, 2026, resulting in the issuance of an aggregate of 25,300,000 units (the “Units”). Each Unit consists of one Class A ordinary share of the Company, par value $0.0001 per share (each an “Class A Ordinary Share”), and one right to receive one-fifth of a Class A Ordinary Share (a “Public Right”), with each five rights entitling the holder thereof to receive one Class A Ordinary Share upon the consummation of an initial business combination. The Units were sold at a price of $10.00 per Unit, and the IPO generated gross proceeds to the Company of $253,000,000. As also previously disclosed in the IPO Closing 8-K, simultaneously with the closing of the IPO, the Company completed the private sale and issuance of an aggregate of 107,500 units (the “Private Placement Units”) to GigAcquisitions9 Corp. (the “Sponsor”), three of the Company’s directors, certain other GigCapital Global advisors and Lynrock Lake Master Fund LP at a price of $9.7374 per unit, generating gross proceeds to the Company of $1,046,771. Each Private Placement Unit consists of one Class A Ordinary Share and one right to receive one-fifth of a Class A Ordinary Share, with each five rights entitling the holder thereof to receive one Class A Ordinary Share upon the consummation of an initial business combination. In addition, as also previously disclosed in the IPO Closing 8-K, simultaneously with the closing of the IPO, the Company completed the private sale and issuance to certain non-managing investors (none of which are affiliated with any member of the Company’s management, the Sponsor or any other investor) of (i) an aggregate of 3,178,430 Class B ordinary shares of the Company, par value of $0.0001 per share (“Class B Ordinary Shares”) at a price of $0.023254 per share and (ii) an aggregate of 281,454 Private Placement Units at a price of $9.7374 per unit, generating gross proceeds to the Company of $2,814,541. A total of $253,000,000 of the proceeds received by the Company from the IPO and the above-described private placements, were placed in a U.S.-based trust account at JPMorgan Chase Bank, N.A. maintained by Continental Stock Transfer & Trust Company, acting as trustee. An audited balance sheet as of January 28, 2026, reflecting receipt of the proceeds upon consummation of the IPO, and the sale of the Private Placement Units and Class B Ordinary Shares has been issued by the Company and is included as Exhibit 99.1 to this Current Report on Form 8-K.