Material Agreement, Financial Obligation, Private Placement (Form 8-K)

Item 1.01 Entry Into a Material Definitive Agreement.

On February 12, 2026, Black Hawk Acquisition Corp., a Cayman Islands exempted company (the "Company"), issued a convertible promissory note (the "Note") in the principal amount of up to $300,000 toBlack Hawk Management LLC (the "Sponsor"). The Note was issued in connection with advances the Sponsor has made, and may make in the future, to the Company for working capital expenses.

The Note bears interest at a rate of 10% per annum and is due and payable upon the occurrence of (i) the closing of the Company's initial business combination (a "DeSPAC Transaction") or (ii) the liquidation of the Company. In the event of a liquidation, all amounts due under the Note will be repaid in cash. In the event of a DeSPAC Transaction, the Sponsor may elect to receive repayment in cash or to convert the outstanding principal balance of the Note into ordinary shares of the post-business combination company at a conversion price of $1.00 per share.

If converted, the number of shares issuable will equal the portion of the principal amount being converted divided by $1.00, rounded up to the nearest whole share. The conversion shares will be entitled to registration rights and the holders will enter into a registration rights agreement with the post-DeSPAC company consistent with the Company's existing registration rights agreement.

The issuance of the Note was made pursuant to the exemption from registration contained in Section 4(a)(2) of the Securities Act of 1933, as amended (the "Securities Act").

The foregoing description is qualified in its entirety by reference to the Note, a copy of which is attached as Exhibit 10.1 hereto and is incorporated herein by reference.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The disclosure set forth above under Item 1.01 is incorporated herein by reference.

Item 3.02 Unregistered Sales of Equity Securities.

To the extent the Note may be converted into ordinary shares upon the closing of a DeSPAC Transaction, such shares will be issued in reliance on the exemption from registration provided by Section 4(a)(2) of the Securities Act, as a transaction not involving a public offering.