Ouster officer plans $520K stock sale for taxes

Officer Spencer Darien filed a Rule 144 notice to sell Ouster, Inc. common stock mainly to cover tax withholding on vested restricted stock units.

Rhea-AI Filing Summary

Ouster, Inc. (OUST) received a Rule 144 notice for proposed sales of its common stock by officer Spencer Darien through E*TRADE Financial Corporation. The notice covers the potential sale of 13,882 shares of common stock on or after September 11, 2026, with an indicated aggregate market value of $520,436.18.

The shares relate to vested or vesting restricted stock units granted under an incentive award plan, with grants dated March 16, 2023, March 21, 2025, and April 11, 2026 totaling 24,177 underlying shares. The filer states that shares are to be sold to cover withholding taxes upon vesting of these restricted stock units. The notice also reports prior sales in the last three months.

Key Figures

Shares proposed to be sold: 13,882 shares Aggregate market value of proposed sale: $520,436.18 Shares outstanding: 72,112,333 shares +4 more

7 metrics

Shares proposed to be sold 13,882 shares Common stock covered by Rule 144 filing, with sale date September 11, 2026

Aggregate market value of proposed sale $520,436.18 Estimated value of 13,882 Ouster, Inc. shares to be sold

Shares outstanding 72,112,333 shares Ouster, Inc. common stock outstanding referenced in the notice

RSU-related shares 24,177 shares Underlying common shares from three restricted stock unit awards

Recent sale on August 4, 2026 30,000 shares for $1,350,000.00 Common stock sold by Spencer Darien during the past three months

Recent sale on June 12, 2026 12,559 shares for $487,578.06 Common stock sold by Spencer Darien during the past three months

Individual RSU award sizes 7,000; 13,333; 3,844 shares Three restricted stock unit awards under incentive award plan

Key Terms

Rule 144, restricted stock units, withholding taxes, incentive award plan

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

restricted stock units financial

"Restricted stock units awarded under incentive award plan"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

withholding taxes financial

"Shares are to be sold to cover withholding taxes upon vesting"

Withholding taxes are amounts a payer or government takes out of payments — such as wages, interest, or dividends — before the recipient gets the money, functioning like a cashier keeping part of a bill to pay taxes on your behalf. For investors this matters because it reduces the cash they actually receive, affects net returns and yield calculations, and may require additional paperwork or treaty claims to recover or offset the withheld amount against final tax bills.

incentive award plan financial

"Restricted stock units awarded under incentive award plan"

An incentive award plan is a formal program that rewards employees, executives, or directors with cash, stock, options, or other pay when the company meets set goals or performance targets. Like a sales commission or a loyalty program that pays out when you hit milestones, it’s designed to align staff behavior with company objectives; investors care because it affects a company’s costs, share count (dilution), leadership incentives, and long-term value creation.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does the Form 144 filing disclose for OUST (Ouster, Inc.)?

The filing discloses that officer Spencer Darien may sell 13,882 shares of Ouster, Inc. common stock under Rule 144 through E*TRADE Financial Corporation, with an indicated aggregate market value of $520,436.18, beginning on or after September 11, 2026.

Why are OUST shares being sold according to this Form 144?

The filer states that the shares are to be sold to cover withholding taxes upon vesting of restricted stock units that were awarded under Ouster, Inc.’s incentive award plan in connection with services rendered.

How many OUST shares are tied to the reported restricted stock unit awards?

The notice lists three restricted stock unit awards under an incentive plan, covering 7,000, 13,333, and 3,844 shares of common stock, for a total of 24,177 underlying shares, all associated with services rendered to Ouster, Inc.

What prior OUST stock sales by Spencer Darien are reported in the last three months?

The filing reports that Spencer Darien sold 30,000 shares of Ouster common stock on August 4, 2026 for $1,350,000.00 and 12,559 shares on June 12, 2026 for $487,578.06.

What is the reported number of OUST shares outstanding in this notice?

The notice states that Ouster, Inc. had 72,112,333 shares of common stock outstanding in connection with the Rule 144 disclosure, providing context for the 13,882 shares proposed to be sold.

Who signed the Form 144 for the OUST transaction?

The notice is signed by Megan Chung as Attorney-in-Fact for Spencer Darien, indicating that she signed on Darien’s behalf for this Rule 144 filing concerning Ouster, Inc. common stock.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 09/11/2026 - 09:12 PM Accepted by SEC EDGAR 09/11/2026 - 09:11 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001226378
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Ouster, Inc.
SEC File Number	001-39463
Address of Issuer	350 TREAT AVENUE SAN FRANCISCO CALIFORNIA 94110
Phone	(415) 949-0108
Name of Person for Whose Account the Securities are To Be Sold	SPENCER DARIEN
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common Stock	ETRADE FINANCIAL CORPORATION 3 EDISON DRIVE ALPHARETTA GA 30005	13882	520436.18	72112333	09/11/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common Stock	09/11/2026	Restricted stock units awarded under incentive award plan	Issuer			7000	03/16/2023	Services rendered
Common Stock	09/11/2026	Restricted stock units awarded under incentive award plan	Issuer			13333	03/21/2025	Services rendered
Common Stock	09/11/2026	Restricted stock units awarded under incentive award plan	Issuer			3844	04/11/2026	Services Rendered

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Darien Spencer 350 TREAT AVENUE SAN FRANCISCO CA 94110	Common Stock	08/04/2026	30000	1350000.00
Darien Spencer 350 TREAT AVENUE SAN FRANCISCO CA 94110	Common Stock	06/12/2026	12559	487578.06

144: Remarks and Signature

Remarks	Shares are to be sold to cover withholding taxes upon vesting of restricted stock units.
Date of Notice	09/11/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	08/19/2025
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Megan Chung, as Attorney-in-Fact for Darien Spencer
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)