AMPX Form 144: 2,000-Share Vesting; Insider Sales Listed

Amprius Holdings, Inc. (AMPX) reported Form 144 notices for proposed sales of Common Stock.

Rhea-AI Filing Summary

Amprius Holdings, Inc. (AMPX) reported Form 144 notices for proposed sales of Common Stock. The filing lists a restricted stock vesting distribution of 2,000 shares on 05/20/2026 and multiple share sale notifications by Thomas Stepien totaling 64,977 shares across dates in May 2026.

The transactions are described as sales or dispositions under Rule 144 tied to services-rendered vesting and open-market sales; cash-flow treatment and buyer counterparties are not specified in the provided excerpt.

Insights

Securities Compliance Analyst

Rule 144 sale notices and a vesting distribution are disclosed.

The excerpt lists a 2,000-share restricted stock vesting under a registered plan on 05/20/2026 and multiple Form 144 sale entries by Thomas Stepien on 05/21/2026 and 05/27/2026. These are notifications required when holders intend to sell restricted or control securities.

Timing and proceeds details are not provided here; subsequent Form 4/144 settlement entries or broker reports would show execution and cash flows.

Key Figures

Restricted stock vesting: 2,000 shares Sale notice - 05/21/2026 (line 1): 46,918 shares Sale notice - 05/21/2026 (line 2): 13,784 shares +3 more

6 metrics

Restricted stock vesting 2,000 shares vested under a registered plan on 05/20/2026

Sale notice - 05/21/2026 (line 1) 46,918 shares Form 144 sale entry dated 05/21/2026 by Thomas Stepien

Sale notice - 05/21/2026 (line 2) 13,784 shares Form 144 sale entry dated 05/21/2026 by Thomas Stepien

Sale notice - 05/27/2026 4,375 shares Form 144 sale entry dated 05/27/2026 by Thomas Stepien

Aggregate noted shares (sum of listed sales) 64,977 shares sum of the three Thomas Stepien sale lines in May 2026

Dollar value line examples $75221.56; $693,842.15; $203,843.31 per-line dollar figures listed alongside sale entries in the excerpt

Key Terms

Form 144, Restricted Stock Vesting, Rule 144

3 terms

Form 144 regulatory

"144: Securities To Be Sold"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Restricted Stock Vesting financial

"Restricted Stock Vesting Under a Registered Plan"

Restricted stock vesting is the timetable and conditions under which shares granted to employees or insiders become fully owned and can be sold, typically requiring continued work or meeting performance goals. It matters to investors because large blocks of shares can become tradable at once, which can change share supply and price, and because vesting aligns insiders’ incentives with the company’s long‑term performance—think of it like a timed unlock that both rewards and locks in key people.

Rule 144 regulatory

"Securities To Be Sold / Restricted Stock Vesting Under a Registered Plan"

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.

FAQ

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

What does the AMPX Form 144 filing report?

The filing reports proposed sales of Common Stock under Rule 144. It shows a 2,000-share restricted stock vesting on 05/20/2026 and sale notifications by Thomas Stepien totaling 64,977 shares across May 2026.

Who is the selling party named in the AMPX excerpt?

The excerpt names Thomas Stepien as a reporting seller. The entries list specific sale notices on 05/21/2026 and 05/27/2026 with share amounts and dollar values included in the lines provided.

Does the Form 144 excerpt state proceeds or counterparties?

No. The provided excerpt does not state final cash proceeds or buyer counterparties. It lists share counts, dates, and dollar figures per sale line, but settlement details and receiving parties are not included in the excerpt.

What is the 2,000-share entry dated 05/20/2026?

That line describes restricted stock vesting under a registered plan for 2,000 shares on 05/20/2026, attributed to services rendered. It shows the shares becoming eligible for sale under Rule 144 notification requirements.

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

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Accepted by SEC EDGAR 06/04/2026 - 04:18 PM EDT 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	0002067233
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	AMPRIUS TECHNOLOGIES, INC.
SEC File Number	001-41314
Address of Issuer	1180 PAGE AVENUE FREMONT CALIFORNIA 94538
Phone	(800) 425-8803
Name of Person for Whose Account the Securities are To Be Sold	THOMAS M STEPIEN
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
Relationship to Issuer	Director

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	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	2000	41940.00	144354000	06/04/2026	NYSE

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	05/20/2026	Restricted Stock Vesting Under a Registered Plan	Issuer			2000	05/20/2026	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
Thomas Stepien 1180 Page Avenue Fremont CA 94538	Amprius (AMPX)	05/27/2026	4375	75221.56
Thomas Stepien 1180 Page Avenue Fremont CA 94538	Amprius (AMPX)	05/21/2026	46918	693842.15
Thomas Stepien 1180 Page Avenue Fremont CA 94538	Amprius (AMPX)	05/21/2026	13784	203843.31

144: Remarks and Signature

Remarks
Date of Notice	06/04/2026
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/ Thomas M Stepien
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)