Sec Form 4 Filing - SANDERSON MATTHEW @ TETRA TECHNOLOGIES INC - 2024-03-15

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 SANDERSON MATTHEW 2. Issuer Name and Ticker or Trading Symbol TETRA TECHNOLOGIES INC [ TTI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Executive Vice President (Last) (First) (Middle) 24955 INTERSTATE 45 N 3. Date of Earliest Transaction (MM/DD/YY) 03/15/2024 (Street) THE WOODLANDS, TX77380 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

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 $ 0 ( 1 ) 03/15/2024 A 42,758 ( 2 ) 03/31/2025 Common Stock 42,758 $ 0 42,758 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SANDERSON MATTHEW 24955 INTERSTATE 45 N THE WOODLANDS, TX77380 Executive Vice President Signatures Kimberly M. O'Brien, attorney in fact 03/19/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Each restricted stock unit ("RSU") represents the contingent right to receive one share of Issuer's common stock upon vesting of the unit. The closing price of the Issuer's common stock on the date of this RSU award was $4.27. ( 2 )Upon the Reporting Person's election, a significant portion of the annual bonus earned by the Reporting Person for the 2023 performance year was settled in restricted stock units ("RSUs") rather than cash. The RSU was granted pursuant to the TETRA Technologies, Inc. Second Amended and Restated 2018 Equity Incentive Plan. One hundred percent of the award will vest on March 15, 2025, subject to continued service on the vesting date. Vested shares will be delivered to the reporting person on the settlement date unless the Issuer elects to settle the RSUs in cash, or a combination of shares and cash, in the Issuer's sole discretion.

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).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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