X0508 4 2025-12-10 0 0001776909 CuriosityStream Inc. CURI 0001827522 Cudahy Theresa Ellen 8484 GEORGIA AVE., SUITE 700 SILVER SPRING MD 20910 0 1 0 0 COO and Secretary 1 Common Stock 2025-12-10 4 S 0 5768 4.976 D 508880 D Restricted Stock Units Common Stock 750000 750000 D Shares sold pursuant to a 10b5-1 plan which Ms. Cudahy entered into on August 13, 2025. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $4.97 to $4.99, inclusive. The reporting person undertakes to provide to CuriosityStream Inc., any security holder of CuriosityStream Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote to this Form 4. On July 25, 2025 ("Grant Date"), the Company granted Ms. Cudahy 750,000 restricted stock units ("RSUs") with tandem dividend equivalent rights under the Company's 2020 Omnibus Incentive Plan (the "Plan"). Each RSU represents a contingent right to receive one share of common stock. The RSUs granted are performance-based and will vest in four tranches of 187,500 each upon the date the Board determines that the applicable performance condition has been achieved. In the event that the performance conditions are not met, the RSUs granted will vest in four equal installments of 187,500 on each of the first, second, third and fourth anniversaries of the Grant Date, and will be settled upon vesting (or within 30 days thereafter). All vesting events are subject to continued employment on each applicable vesting date. /s/ P. Brady Hayden as attorney-in-fact for Tia Cudahy 2025-12-12