Comparable stake leader
BlackRock, Inc.
SEC ownership of Amprius Technologies, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001899287.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
09 Jun 2026
- Public ticker
- AMPX, AMPX-WT on NYSE
- Parsed ownership sources
-
13F, 13D/G, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
BlackRock, Inc.
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
BlackRock, Inc.
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
09 Jun 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001899287
- Issuer location
- Fremont, CA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Amprius Technologies, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
BlackRock, Inc.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
09 Jun 2026
13F
13D/G
3/4/5
Lead comparable stake: 5.8%
13D/G row: BlackRock, Inc.
Showing 1-8 of 50 holder rows.
Quick read
BlackRock, Inc. leads the comparable SEC ownership view at 5.8%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens BlackRock, Inc.'s linked filing trail.
Comparable ownership
Top 5
BlackRock, Inc.
5.8%
JANE STREET GROUP, LLC
5.1%
Alan E. Salzman
2.6%
Sandra Wallach
0.73%
Constantin Ionel Stefan
0.58%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| BlackRock, Inc. |
13F
13D/G
Company
|
5.8%
from 13D/G
|
$155,543,800
9,225,611 shares
|
— | 31 Mar 2026 |
| JANE STREET GROUP, LLC |
13D/G
13F
Company
|
5.1%
|
$118,269,258
7,014,784 shares
|
$0 | 22 Apr 2026 |
| Alan E. Salzman |
13D/G
SALZMAN ALAN E
|
2.6%
|
$20,047,668
3,112,992 shares
|
$0 | 06 Aug 2025 |
| Sandra Wallach |
3/4/5
Chief Financial Officer
|
0.73%
|
$6,852,155
1,005,275 shares
|
-$193,512 | 21 Aug 2025 |
| Constantin Ionel Stefan |
3/4/5
Chief Technology Officer
|
0.58%
|
$13,777,323
801,310 shares
|
-$10,511,968 | 27 May 2026 |
| Donald R. Dixon |
3/4/5
Director
|
0.52%
|
$13,047,389
714,036 shares
|
-$1,085,452 | 09 Jun 2026 |
| Thomas M. Stepien |
3/4/5
Chief Executive Officer, Director
|
0.48%
|
$13,741,726
662,539 shares
|
-$1,014,847 | 04 Jun 2026 |
| Ricardo C. Rodriguez |
3/4/5
Chief Financial Officer
|
0.25%
|
$4,042,500
350,000 shares
|
— | 04 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$83,718,022.
Buys
$0
Insiders: 0
Sells
$83,718,022
Insiders: 7
Net
-$83,718,022
Shares: -6,277,507
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 6,277,507
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 1,943,013 | $0 | $31,546,370 | -$31,546,370 |
| 3-6 | 0 | 2,929,357 | $0 | $37,776,949 | -$37,776,949 |
| 6-9 | 0 | 1,291,934 | $0 | $13,623,089 | -$13,623,089 |
| 9-12 | 0 | 113,203 | $0 | $771,614 | -$771,614 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 25 reporting-owner rows connected to Amprius Technologies, Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
25
Largest Forms 3/4/5 holder
Kang Sun
Net 12M change
-$83,718,021
Latest report
09 Jun 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| Kang Sun | Director | $22,967,247 | -$57,428,225 | -71% | Mixed | 27 May 2026 |
| Constantin Ionel Stefan | Chief Technology Officer | $13,777,323 | -$10,511,968 | -43% | Filing P/S | 27 May 2026 |
| Thomas M. Stepien | Chief Executive Officer, Director | $13,741,726 | -$1,014,847 | -6.9% | Mixed | 04 Jun 2026 |
| Donald R. Dixon | Director | $13,047,389 | -$1,085,452 | -7.7% | Mixed | 09 Jun 2026 |
| Sandra Wallach | Chief Financial Officer | $6,852,155 | -$193,512 | -2.7% | Filing P/S | 21 Aug 2025 |
| Ricardo C. Rodriguez | Chief Financial Officer | $4,042,500 | Mixed | 04 Mar 2026 | ||
| Steven Chu | Director | $2,360,177 | -$5,863,984 | -71% | Filing P/S | 10 Mar 2026 |
| Amprius, Inc. | 10%+ Owner | $2,012,807 | Mixed | 23 Oct 2024 | ||
| Justin E. Mirro | Director | $1,077,140 | Mixed | 03 Sep 2024 | ||
| Livingston Satterthwaite | Director | $846,929 | Mixed | 13 Jun 2025 | ||
| Wen Hsuan Hsieh | Director | $809,911 | -$7,620,033 | -90% | Filing P/S | 12 Mar 2026 |
| Kathleen A. Bayless | Director | $518,356 | Mixed | 13 Jun 2025 | ||
| Jonathan Bornstein | President of Amprius Lab | $414,215 | Mixed | 10 Mar 2025 | ||
| Mary E. Gustanski | Director | $198,513 | Mixed | 07 Jun 2024 | ||
| Kensington Capital Sponsor IV LLC | Other* | Mixed | 14 Sep 2022 | |||
| Daniel Elliot Huber | Chief Financial Officer | Mixed | 01 Mar 2022 | |||
| Robert J. Remenar Under Power | Chief Operating Officer | Mixed | 01 Mar 2022 | |||
| Nicole Nason | Director | Mixed | 01 Mar 2022 | |||
| Donald L. Runkle | Director | Mixed | 01 Mar 2022 | |||
| Matthew J. Simoncini | Director | Mixed | 01 Mar 2022 |
Recent insider transactions for Amprius Technologies, Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Donald R. Dixon | AMPX | Common stock | Sale | -8.26% | $765,200 | $19.13 | -40,000 | 444,380 | 09 Jun 2026 | See Footnote |
| Thomas M. Stepien | AMPX | Common stock | Sale | -0.32% | $41,940 | $20.97 | -2,000 | 625,625 | 04 Jun 2026 | Direct |
| Thomas M. Stepien | AMPX | Common stock | Gift | 36,914 | 36,914 | 04 Jun 2026 | See Footnote | |||
| Thomas M. Stepien | AMPX | Common stock | Gift | -9.68% | -67,298 | 627,625 | 04 Jun 2026 | Direct | ||
| Kang Sun | AMPX | Common stock | Sale | -0.03% | $6,121 | $17.19 | -356 | 1,280,498 | 27 May 2026 | Direct |
| Thomas M. Stepien | AMPX | Common stock | Sale | -0.63% | $75,222 | $17.19 | -4,375 | 694,923 | 27 May 2026 | Direct |
| Constantin Ionel Stefan | AMPX | Common stock | Sale | -0.4% | $55,157 | $17.19 | -3,208 | 801,310 | 27 May 2026 | Direct |
| Donald R. Dixon | AMPX | Common stock | Sale | -3.56% | $320,252 | $17.90 | -17,895 | 484,380 | 26 May 2026 | See Footnote |
| Kang Sun | AMPX | Common stock | Sale | -5.03% | $1,002,594 | $14.79 | -67,796 | 1,280,854 | 21 May 2026 | Direct |
| Constantin Ionel Stefan | AMPX | Common stock | Sale | -3.46% | $426,083 | $14.79 | -28,812 | 804,518 | 21 May 2026 | Direct |
| Thomas M. Stepien | AMPX | Common stock | Sale | -7.99% | $897,685 | $14.79 | -60,702 | 699,298 | 21 May 2026 | Direct |
| Kang Sun | AMPX | Common stock | Award | 0.47% | 6,250 | 1,348,650 | 05 May 2026 | Direct | ||
| Kang Sun | AMPX | Common stock | Sale | -52.8% | $23,860,714 | $15.91 | -1,500,000 | 1,342,400 | 01 Apr 2026 | Direct |
| Kang Sun | AMPX | Common stock | Options Exercise | 111.7% | 1,500,000 | 2,842,400 | 01 Apr 2026 | Direct | ||
| Kang Sun | AMPX | Stock Option (right to buy) | Options Exercise | -100% | -1,500,000 | 0 | 01 Apr 2026 | Direct | ||
| Kang Sun | AMPX | Common stock | Sale | -79.4% | $4,095,402 | $18.80 | -217,869 | 56,406 | 23 Mar 2026 | See Footnote |
| Wen Hsuan Hsieh | AMPX | Common stock | Sale | -90.3% | $7,620,033 | $18.44 | -413,146 | 44,444 | 12 Mar 2026 | Direct |
| Wen Hsuan Hsieh | AMPX | Common stock | Options Exercise | 144.3% | 270,251 | 457,590 | 12 Mar 2026 | Direct | ||
| Wen Hsuan Hsieh | AMPX | Stock Option (right to buy) | Options Exercise | -100% | -270,251 | 0 | 12 Mar 2026 | Direct | ||
| Steven Chu | AMPX | Common stock | Sale | -55% | $2,878,555 | $18.50 | -155,565 | 127,339 | 12 Mar 2026 | Direct |
| Steven Chu | AMPX | Common stock | Options Exercise | 122.2% | 155,565 | 282,904 | 12 Mar 2026 | Direct | ||
| Steven Chu | AMPX | Stock Option (right to buy) | Options Exercise | -100% | -155,565 | 0 | 12 Mar 2026 | Direct | ||
| Steven Chu | AMPX | Common stock | Sale | -56.7% | $2,985,429 | $17.92 | -166,632 | 127,339 | 10 Mar 2026 | Direct |
| Steven Chu | AMPX | Common stock | Options Exercise | 54.8% | 104,132 | 293,971 | 10 Mar 2026 | Direct | ||
| Steven Chu | AMPX | Stock Option (right to buy) | Options Exercise | -60% | -104,132 | 69,422 | 10 Mar 2026 | Direct | ||
| Ricardo C. Rodriguez | AMPX | Common stock | Award | 75% | 150,000 | 350,000 | 04 Mar 2026 | Direct | ||
| Thomas M. Stepien | AMPX | Common stock | Award | 24.6% | 150,000 | 760,000 | 04 Mar 2026 | Direct | ||
| Constantin Ionel Stefan | AMPX | Common stock | Award | 15.2% | 110,000 | 833,330 | 04 Mar 2026 | Direct | ||
| Kang Sun | AMPX | Common stock | Sale | -4.36% | $622,035 | $10.16 | -61,251 | 1,342,400 | 23 Feb 2026 | Direct |
| Constantin Ionel Stefan | AMPX | Common stock | Sale | -3.39% | $257,604 | $10.16 | -25,366 | 723,330 | 23 Feb 2026 | Direct |
| Constantin Ionel Stefan | AMPX | Common stock | Sale | -5.03% | $476,351 | $12.00 | -39,690 | 748,696 | 28 Jan 2026 | Direct |
| Constantin Ionel Stefan | AMPX | Common stock | Options Exercise | 5.3% | 39,690 | 788,386 | 28 Jan 2026 | Direct | ||
| Constantin Ionel Stefan | AMPX | Stock Option (right to buy) | Options Exercise | -100% | -39,690 | 0 | 28 Jan 2026 | Direct | ||
| Constantin Ionel Stefan | AMPX | Common stock | Sale | -0.21% | $19,200 | $12.00 | -1,600 | 748,696 | 23 Jan 2026 | Direct |
| Constantin Ionel Stefan | AMPX | Common stock | Options Exercise | 0.21% | 1,600 | 750,296 | 23 Jan 2026 | Direct | ||
| Constantin Ionel Stefan | AMPX | Stock Option (right to buy) | Options Exercise | -3.88% | -1,600 | 39,600 | 23 Jan 2026 | Direct | ||
| Constantin Ionel Stefan | AMPX | Common stock | Sale | -39.7% | $5,931,912 | $12.04 | -492,827 | 748,696 | 22 Jan 2026 | Direct |
| Constantin Ionel Stefan | AMPX | Common stock | Options Exercise | 65.8% | 492,827 | 1,241,523 | 22 Jan 2026 | Direct | ||
| Constantin Ionel Stefan | AMPX | Stock Option (right to buy) | Options Exercise | -100% | -492,827 | 0 | 22 Jan 2026 | Direct | ||
| Constantin Ionel Stefan | AMPX | Common stock | Sale | -8.92% | $879,411 | $12.00 | -73,280 | 748,696 | 21 Jan 2026 | Direct |
| Constantin Ionel Stefan | AMPX | Common stock | Options Exercise | 9.79% | 73,280 | 821,976 | 21 Jan 2026 | Direct | ||
| Constantin Ionel Stefan | AMPX | Stock Option (right to buy) | Options Exercise | -99.9% | -73,280 | 90 | 21 Jan 2026 | Direct | ||
| Kang Sun | AMPX | Common stock | Sale | -2.98% | $476,274 | $11.03 | -43,185 | 1,403,651 | 20 Jan 2026 | Direct |
| Kang Sun | AMPX | Common stock | Options Exercise | 3.08% | 43,185 | 1,446,836 | 20 Jan 2026 | Direct | ||
| Kang Sun | AMPX | Stock Option (right to buy) | Options Exercise | -3.19% | -43,185 | 1,312,505 | 20 Jan 2026 | Direct | ||
| Kang Sun | AMPX | Common stock | Sale | -40.4% | $10,518,669 | $11.07 | -950,548 | 1,403,651 | 16 Jan 2026 | Direct |
| Kang Sun | AMPX | Common stock | Options Exercise | 67.7% | 950,548 | 2,354,199 | 16 Jan 2026 | Direct | ||
| Kang Sun | AMPX | Stock Option (right to buy) | Options Exercise | -100% | -950,548 | 0 | 16 Jan 2026 | Direct | ||
| Kang Sun | AMPX | Common stock | Sale | -26.5% | $5,111,474 | $10.10 | -506,267 | 1,403,651 | 12 Jan 2026 | Direct |
| Kang Sun | AMPX | Common stock | Options Exercise | 36.1% | 506,267 | 1,909,918 | 12 Jan 2026 | Direct |
* marks a reported price that did not pass the local price check.