Sec Form 4 Filing - Stinchcomb Clinton Larry @ CuriosityStream Inc. - 2026-05-28

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Stinchcomb Clinton Larry 2. Issuer Name and Ticker or Trading Symbol CuriosityStream Inc. [ CURI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) President and CEO (Last) (First) (Middle) 8484 GEORGIA AVE., SUITE 700 3. Date of Earliest Transaction (MM/DD/YY) 05/28/2026 (Street) SILVER SPRING, MD20910 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/28/2026 P 25,744 A $ 2.777 ( 1 ) 2,971,260 D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Restricted Stock Units ( 2 ) ( 3 ) ( 2 )( 3 ) ( 2 )( 3 ) Common Stock 1,200,000 1,200,000 ( 2 ) ( 3 ) D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Stinchcomb Clinton Larry 8484 GEORGIA AVE., SUITE 700 SILVER SPRING, MD20910 X President and CEO Signatures /s/ P. Brady Hayden as attorney-in-fact for Clint Stinchcomb 06/01/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $2.75 to $2.78, 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 purchased at each separate price within the ranges set forth in this footnote to this Form 4. ( 2 )On July 15, 2025, the Company granted Mr. Stinchcomb 2,400,000 restricted stock units (RSUs) with tandem dividend equivalent rights under the 2020 Omnibus Incentive Plan. Each RSU represents the right to receive one share of common stock and will be settled upon vesting (or within 30 days thereafter). All vesting events are subject to continued employment on each applicable vesting date. The RSUs granted are performance-based, subject to the Company achieving certain stock price or financial performance goals. ( 3 )On August 4, 2025, the Board determined that the Company met the first performance condition of the award by achieving 35% year-over-year revenue growth for the period January 1 through June 30, 2025, compared to the same period in 2024, and thereby triggering the vesting of the first tranche of the Award, or 600,000 RSUs. On March 10, 2026, the Board determined that the Company met the second performance condition of the award by achieving 40% revenue growth and 35% adjusted free cash flow growth for the full year 2025 compared to 2024, and thereby triggering the vesting of the second tranche of the Award, or 600,000 RSUs. Mr. Stinchcomb now has 1,200,000 remaining unvested RSUs under the award as reported in Table II.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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