Ouster officer plans $763K stock sale for taxes

Ouster officer Mark Frichtl filed a Rule 144 notice to sell shares mainly to cover tax withholding on vested RSUs.

Rhea-AI Filing Summary

Ouster, Inc. (OUST) received a notice that officer Mark Frichtl intends to sell common stock under Rule 144. The notice covers up to 20,353 shares of common stock, with an aggregate market value of $763,033.97 and 72,112,333 shares of common stock outstanding as of September 11, 2026.

The shares relate to restricted stock unit (RSU) awards granted under an incentive award plan, and the filing states that shares are to be sold to cover withholding taxes upon vesting of these RSUs. The notice also lists several common stock sales by Mark Frichtl during the prior three months.

Key Figures

Shares to be sold under Rule 144: 20,353 shares Aggregate market value of shares to be sold: $763,033.97 Shares outstanding: 72,112,333 shares +5 more

8 metrics

Shares to be sold under Rule 144 20,353 shares Common stock covered by the notice for planned sale

Aggregate market value of shares to be sold $763,033.97 Market value associated with the 20,353 shares in the notice

Shares outstanding 72,112,333 shares Ouster common stock outstanding as of September 11, 2026

RSU-related shares (first award) 29,166 shares Common stock from RSU award acquired April 1, 2025

RSU-related shares (second award) 6,285 shares Common stock from RSU award acquired April 11, 2026

Sale on June 12, 2026 18,414 shares for $714,886.72 Common stock sold by Mark Frichtl in past three months

Sale on August 26, 2026 100,000 shares for $1,422,000.00 Common stock sold by Mark Frichtl in past three months

Sale on September 2, 2026 38,745 shares for $0.00 Common stock transaction reported in past three months

Key Terms

Rule 144, restricted stock unit awards, incentive award plan, withholding taxes

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 unit awards financial

"Restricted stock unit awards awarded under incentive award plan"

Restricted stock unit awards are company promises to deliver a specific number of shares to employees or service providers in the future once conditions—such as staying with the company for a set time or meeting performance targets—are met. They matter to investors because when the promises convert into actual shares they increase the total share count and can reduce earnings per share, while also aligning recipients’ interests with stock performance much like deferred pay that turns into ownership if goals are met.

incentive award plan financial

"Restricted stock unit awards 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.

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.

FAQ

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

What does OUST’s Form 144 filing by Mark Frichtl disclose?

It discloses that officer Mark Frichtl intends to sell up to 20,353 shares of Ouster common stock under Rule 144, primarily to cover withholding taxes upon vesting of restricted stock unit (RSU) awards granted under an incentive award plan.

How many OUST shares are covered by the planned Rule 144 sale?

The notice covers up to 20,353 shares of Ouster common stock with an aggregate market value of $763,033.97 as listed in the securities information section of the filing.

What RSU awards are involved in the OUST Form 144 filing?

The filing lists 29,166 shares and 6,285 shares of common stock issuable from restricted stock unit awards granted under an incentive award plan, acquired on April 1, 2025 and April 11, 2026, respectively, with shares to be sold to cover withholding taxes upon vesting.

What OUST stock sales has Mark Frichtl made in the past three months?

The filing reports sales of Ouster common stock: 18,414 shares on June 12, 2026 for $714,886.72, 100,000 shares on August 26, 2026 for $1,422,000.00, and 38,745 shares on September 2, 2026 with an amount listed as $0.00.

How many OUST shares were outstanding at the time of the Form 144 notice?

The filing states that 72,112,333 shares of Ouster common stock were outstanding as of September 11, 2026; this is a baseline figure for the company’s share count, not the number of shares covered by the notice.

What reason does the OUST Form 144 give for the planned share sales?

The remarks state that the shares are to be sold to cover withholding taxes upon vesting of restricted stock units, indicating a tax-related purpose tied to equity compensation rather than a separate financing transaction.

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

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 09/11/2026 - 09:30 PM Accepted by SEC EDGAR 09/11/2026 - 09:29 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	0001847596
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	Frichtl Mark
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	20353	763033.97	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 unit awards awarded under incentive award plan	Issuer			29166	04/01/2025	Services rendered
Common Stock	09/11/2026	Restricted stock unit awards awarded under incentive award plan	Issuer			6285	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
Mark Frichtl 350 TREAT AVENUE SAN FRANCISCO CA 94110	Common Stock	06/12/2026	18414	714886.72
Mark Frichtl 350 TREAT AVENUE SAN FRANCISCO CA 94110	Common Stock	08/26/2026	100000	1422000.00
Mark Frichtl 350 TREAT AVENUE SAN FRANCISCO CA 94110	Common Stock	09/02/2026	38745	0.00

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	06/09/2025
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 Mark Frichtl
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)