Ouster (NYSE: OUST) CTO sells 15,689 shares in tax-related 10b5-1 trade

Rhea-AI Filing Summary

Ouster, Inc. Chief Technology Officer Mark Frichtl reported an open-market sale of 15,689 shares of common stock on March 12, 2026 at a weighted average price of $23.4328 per share. According to the footnotes, the shares were sold to cover withholding taxes upon the vesting and settlement of restricted stock units pursuant to a Rule 10b5-1 sale-to-cover instruction letter dated June 9, 2025. Following this tax-related sale, Frichtl directly holds 636,882 shares of Ouster common stock.

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

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

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Frichtl Mark

(Last) (First) (Middle)

350 TREAT AVENUE

(Street)

SAN FRANCISCO CA 94110

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Ouster, Inc. [ OUST ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Technology Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/12/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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	03/12/2026		S		15,689(1)	D	$23.4328(2)	636,882	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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. Reflects shares sold to cover withholding taxes incurred upon the vesting and settlement of restricted stock units pursuant to a Rule 10b5-1 sale to cover instruction letter dated June 9, 2025.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.9820 to $23.4522. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, 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 range set forth in this footnote.

	/s/ Megan Chung, as Attorney-in-Fact for Mark Frichtl	03/16/2026
	** Signature of Reporting Person	Date
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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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FAQ

What insider transaction did Ouster (OUST) report for CTO Mark Frichtl?

Ouster reported that CTO Mark Frichtl sold 15,689 shares of common stock. The sale was executed on March 12, 2026 as an open-market transaction and disclosed on a Form 4 insider trading report filed with regulators.

At what price did the Ouster (OUST) CTO sell his shares?

The Ouster CTO’s share sale used a weighted average price of $23.4328 per share. Footnotes explain the stock was sold in multiple trades between $22.9820 and $23.4522, with detailed breakdowns available upon request from the company or regulators.

Why did Ouster (OUST) CTO Mark Frichtl sell 15,689 shares?

The shares were sold to cover withholding taxes triggered by vesting and settlement of restricted stock units. A footnote states this was done under a Rule 10b5-1 sale-to-cover instruction letter dated June 9, 2025, indicating a pre-arranged, tax-related transaction.

How many Ouster (OUST) shares does the CTO hold after this sale?

After the tax-related sale, CTO Mark Frichtl directly holds 636,882 shares of Ouster common stock. This post-transaction holding is reported in the Form 4 and reflects his remaining direct ownership stake following the 15,689-share disposition.

Was the Ouster (OUST) CTO’s share sale under a Rule 10b5-1 plan?

Yes. A footnote explains the sale covered withholding taxes under a Rule 10b5-1 sale-to-cover instruction letter dated June 9, 2025. Such pre-established plans automate trades, often reducing the significance of transaction timing as an informational signal.

What price range did Ouster (OUST) shares sell for in this insider trade?

The Form 4 notes that shares were sold in multiple trades between $22.9820 and $23.4522 per share. The reported $23.4328 figure is a weighted average, and detailed trade-level prices are available from the company or regulators upon request.