BLACKBOXSTOCKS INC.

Rule 10b5-1 Trading Arrangement

On September 15, 2025, Gust Kepler, a member of the Company’s board of directors and the Company’s President and Chief Executive Officer, entered into a Rule 10b5-1 trading arrangement providing for the potential sale of an aggregate of up to 250,000 shares of the Company’s common stock, which represents a portion of Mr. Kepler’s total holdings of common stock in the Company. The trading arrangement is intended to satisfy the affirmative defense in Rule 10b5-1(c) under the Securities Exchange Act of 1934, as amended. The first date that sales of any shares are permitted to be sold under the trading arrangement is the later of (i) the 91st day after the Adoption Date of September 15, 2025 or (ii) the earlier of (a) the third business day following the disclosure of the Company’s financial results in a Form 10-Q or Form 10-K for the completed fiscal quarter in which the trading arrangement is adopted or (b) the 121st day after the Adoption Date of September 15, 2025. Subsequent sales under the trading arrangement may occur from time to time for the term of the trading arrangement which expires September 15, 2026, or earlier if all transactions under the trading arrangement are completed prior to such date or if the trading arrangement is otherwise terminated.