Thomas M. Stepien - 21 Aug 2026 Form 4 Insider Report for Amprius Technologies, Inc. (AMPX)

Reporting relationship: Chief Executive Officer, Director
Issuer ticker: AMPX
Reported as of: 21 Aug 2026
Net transaction value: -$323,553
SEC form: 4
Accepted by SEC: 25 Aug 2026, 17:21:20 UTC
Prior SEC filing: 05 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ Ricardo C. Rodriguez, attorney-in-fact on behalf of Thomas M Stepien

Key filing fact

Thomas M. Stepien filed Form 4 for Amprius Technologies, Inc. (AMPX) on 25 Aug 2026.

Key facts

This page summarizes Thomas M. Stepien's Form 4 filing for Amprius Technologies, Inc. (AMPX).
7 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 25 Aug 2026, 17:21.

Change

Previous filing in this sequence was filed on 05 Jun 2026.
Current net transaction value: -$323,553.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0002067233 Primary reporting owner

Stepien Thomas M

Relationship: Chief Executive Officer, Director
Address: 1180 PAGE AVE., FREMONT
Signature: /s/ Ricardo C. Rodriguez, attorney-in-fact on behalf of Thomas M Stepien
Signature date: 25 Aug 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

AMPX transaction

Common stock

Sale

Transaction value: $243,313
Shares: -23,529
Change %: -3.8%
Price: $10.34
Shares after: 602,096
Date: 21 Aug 2026
Ownership: Direct
Footnotes: F1, F2, F3

AMPX transaction

Common stock

Sale

Transaction value: $80,240
Shares: -8,000
Change %: -1.3%
Price: $10.03
Shares after: 594,096
Date: 24 Aug 2026
Ownership: Direct
Footnotes: F3

AMPX transaction

Common stock

Gift

Transaction value
Shares: -5,000
Change %: -0.84%
Price: $0.000000^*
Shares after: 589,096
Date: 25 Aug 2026
Ownership: Direct
Footnotes: F3, F4

AMPX transaction

Common stock

Gift

Transaction value
Shares: -5,000
Change %: -0.85%
Price: $0.000000^*
Shares after: 584,096
Date: 25 Aug 2026
Ownership: Direct
Footnotes: F3, F4

AMPX transaction

Common stock

Gift

Transaction value
Shares: -5,000
Change %: -0.86%
Price: $0.000000^*
Shares after: 579,096
Date: 25 Aug 2026
Ownership: Direct
Footnotes: F3, F4

AMPX transaction

Common stock

Gift

Transaction value
Shares: -346
Change %: -0.06%
Price: $0.000000^*
Shares after: 578,750
Date: 25 Aug 2026
Ownership: Direct
Footnotes: F3, F5

AMPX transaction

Common stock

Award

Transaction value
Shares: +346
Change %: +0.94%
Price: $0.000000^*
Shares after: 37,260
Date: 25 Aug 2026
Ownership: See Footnote
Footnotes: F5, F6

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 6 footnotes

Footnote F1

This transaction was effected pursuant to non-discretionary, sell-to-cover arrangements mandated by the issuer to fund tax withholding obligations in connection with the vesting of restricted stock units.

Footnote F2

The price reported in Column 4 is an average execution price. These shares were sold in multiple transactions at prices ranging from $10.10 to $10.48, inclusive. The reporting person undertakes to provide to 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 above.

Footnote F3

Includes 568,750 restricted stock units, each of which represents a contingent right to receive one share of the issuer's common stock, subject to the applicable vesting schedule and conditions of each restricted stock unit.

Footnote F4

These transfers were made on the same date as bona fide gifts.

Footnote F5

These securities were transferred by the reporting person to the Rogers Stepien Family Revocable Trust, for which the reporting person and his spouse are co-trustees.

Footnote F6

These securities are held by the Rogers Stepien Family Revocable Trust, for which the reporting person and his spouse are co-trustees.