AMPRIUS TECHNOLOGIES INC AMPX
COMMON STOCK · Common Stock · CUSIP 03214Q108 · ISIN US03214Q1085
- SectorIndustrials
- IndustryMiscellaneous Electrical Machinery, Equipment & Supplies
- HeadquartersFremont, CA
- FilingsSEC EDGAR
* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($2.0m this quarter). Holder counts are more reliable. Shares outstanding: 146.1m as of 2026-07-31, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $13.86. Options: 21 managers hold calls ($211.9m notional), 22 hold puts ($219.0m).
Trends to Q2 2026
Institutional holders
Managers reporting a position, each quarter
Numbers
| Quarter | Holders |
|---|---|
| Q3 2022 | 14 |
| Q4 2022 | 23 |
| Q1 2023 | 27 |
| Q2 2023 | 42 |
| Q3 2023 | 47 |
| Q4 2023 | 50 |
| Q1 2024 | 51 |
| Q2 2024 | 66 |
| Q3 2024 | 67 |
| Q4 2024 | 92 |
| Q1 2025 | 101 |
| Q2 2025 | 122 |
| Q3 2025 | 187 |
| Q4 2025 | 206 |
| Q1 2026 | 245 |
| Q2 2026 | 262 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q3 2024 | 38 | 22 |
| Q4 2024 | 61 | 21 |
| Q1 2025 | 64 | 36 |
| Q2 2025 | 84 | 38 |
| Q3 2025 | 149 | 45 |
| Q4 2025 | 129 | 81 |
| Q1 2026 | 167 | 92 |
| Q2 2026 | 172 | 109 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q3 2025 | $60.3m | $12.9m | 0.21 |
| Q4 2025 | $57.6m | $20.5m | 0.36 |
| Q1 2026 | $219.9m | $122.7m | 0.56 |
| Q2 2026 | $211.9m | $219.0m | 1.03 |
Biggest buyers
| JUPITER ASSET MANAGEMENT LTD | New | +2.1m |
| BlackRock, Inc. | Added | +2.1m |
| MORGAN STANLEY | Added | +1.9m |
| UBS Group AG | Added | +1.8m |
| LMR Partners LLP | New | +1.8m |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | New | +1.2m |
| Point72 Asset Management, L.P. | Added | +1.1m |
| RENAISSANCE TECHNOLOGIES LLC | Added | +1.0m |
| Nearwater Capital Markets, Ltd | New | +1.0m |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | +1.0m |
Biggest sellers
| Driehaus Capital Management LLC | Reduced | -2.4m |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ | Reduced | -1.5m |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC | Sold out | -1.2m |
| MARSHALL WACE, LLP | Reduced | -1.1m |
| JPMORGAN CHASE & CO | Reduced | -1.1m |
| HRT FINANCIAL LP | Sold out | -1.0m |
| JANE STREET GROUP, LLC | Reduced | -759.6k |
| MYDA Advisors LLC | Sold out | -735.0k |
| Science & Technology Partners, L.P. | Sold out | -635.1k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC | Sold out | -532.0k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | $63.3m4.6m shares |
| Point72 Asset Management, L.P. | Added | $29.9m2.2m shares |
| GROUP ONE TRADING LLC | Added | $21.3m1.5m shares |
| CITADEL ADVISORS LLC | Added | $20.8m1.5m shares |
| JANE STREET GROUP, LLC | Added | $18.2m1.3m shares |
| IMC-Chicago, LLC | Added | $14.7m1.1m shares |
| DLD Asset Management, LP | Added | $12.6m912.2k shares |
| PEAK6 LLC | Reduced | $8.3m600.9k shares |
| UBS Group AG | Added | $6.9m500.0k shares |
| SIMPLEX TRADING, LLC | Reduced | $6.4m463.8k shares |
Biggest puts
| JANE STREET GROUP, LLC | Added | $64.0m4.6m shares |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $35.8m2.6m shares |
| CITADEL ADVISORS LLC | Added | $29.0m2.1m shares |
| Point72 Asset Management, L.P. | Added | $15.0m1.1m shares |
| IMC-Chicago, LLC | Added | $14.8m1.1m shares |
| GROUP ONE TRADING LLC | Added | $11.4m820.1k shares |
| D. E. Shaw & Co., Inc. | Added | $11.3m815.0k shares |
| UBS Group AG | Added | $11.1m801.8k shares |
| Parallax Volatility Advisers, L.P. | Unchanged | $5.3m385.0k shares |
| CREDIT AGRICOLE S A | New | $3.5m250.0k shares |
Options at notional value: the value of the shares the contracts control, as filers report them, not what the options cost. Not included in the holders, shares or buying above.
Major shareholders (over 5%)
Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.
| Holder | Stake |
|---|---|
| BlackRock, Inc. 13G · institution +1.6 pts · filed 2026-07-27 | 7.4% |
Fell to 5% or below in the last year: JANE STREET GROUP, LLC (3.3%, 2026-08-10), VANGUARD GROUP INC (0.0%, 2026-03-26)
Insider purchases and sales since 1 Apr 2026
Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.
Officers and directors buying vs selling
Number of people, by quarter (10% owners not included)
Numbers
| Quarter | Buying | Bought | Selling | Sold | Sold under a plan |
|---|---|---|---|---|---|
| Q4 2024 | 0 | — | 4 | $438.0k | — |
| Q1 2025 | 0 | — | 4 | $235.0k | — |
| Q2 2025 | 0 | — | 3 | $286.1k | — |
| Q3 2025 | 0 | — | 3 | $772.0k | — |
| Q4 2025 | 0 | — | 2 | $13.6m | — |
| Q1 2026 | 0 | — | 4 | $41.9m | — |
| Q2 2026 | 0 | — | 4 | $28.9m | — |
| Q3 2026 | 0 | — | 3 | $1.3m | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-08-24 | Stepien Thomas M Chief Executive Officer, director | Sold | $80.2k8.0k shares |
| 2026-08-21 | Sun Kang Director | Sold | $642.1k62.1k shares |
| 2026-08-21 | Stefan Constantin Ionel Chief Technology Officer | Sold | $306.9k29.7k shares |
| 2026-08-21 | Stepien Thomas M Chief Executive Officer, director | Sold | $243.3k23.5k shares |
| 2026-06-15 | DIXON DONALD R Director | Sold | $1.5m85.0k shares |
| 2026-06-09 | DIXON DONALD R Director · See Footnote | Sold | $765.2k40.0k shares |
| 2026-06-04 | Stepien Thomas M Chief Executive Officer, director | Sold | $41.9k2.0k shares |
| 2026-05-27 | Stepien Thomas M Chief Executive Officer, director | Sold | $75.2k4.4k shares |
| 2026-05-27 | Stefan Constantin Ionel Chief Technology Officer | Sold | $55.1k3.2k shares |
| 2026-05-27 | Sun Kang Director | Sold | $6.1k356 shares |
| 2026-05-26 | DIXON DONALD R Director · See Footnote | Sold | $320.3k17.9k shares |
| 2026-05-21 | Sun Kang Director | Sold | $1.0m67.8k shares |
| 2026-05-21 | Stepien Thomas M Chief Executive Officer, director | Sold | $897.8k60.7k shares |
| 2026-05-21 | Stefan Constantin Ionel Chief Technology Officer | Sold | $426.1k28.8k shares |
| 2026-04-01 | Sun Kang Director | Sold | $23.9m1.5m shares |
Their holding: how much the trade added to or took from the insider's holding (direct, or the trust or fund named). The same trade is sometimes reported by more than one insider, such as a fund and the director who represents it; totals count it once. A value is left blank where the reported price is far from the market price (usually a typo).
Holders, Q2 2026
| Manager | Shares | Change |
|---|---|---|
| BlackRock, Inc. 0.00% of their portfolio | 11.3m $157.1m | Added +2.1m |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 5.6m $77.1m | Added +654.1k |
| MORGAN STANLEY 0.00% of their portfolio | 5.1m $70.8m | Added +1.9m |
| TWO SIGMA INVESTMENTS, LP 0.05% of their portfolio | 4.3m $59.9m | Added +812.6k |
| UBS Group AG 0.01% of their portfolio | 4.1m $56.4m | Added +1.8m |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 3.5m $48.8m | Added +706.1k |
| JANE STREET GROUP, LLC 0.03% of their portfolio | 3.4m $47.1m | Reduced -759.6k |
| STATE STREET CORP 0.00% of their portfolio | 3.2m $44.9m | Added +527.7k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 2.5m $35.2m | Added +316.1k |
| JUPITER ASSET MANAGEMENT LTD 0.15% of their portfolio | 2.1m $29.6m | New |
| LMR Partners LLP 0.18% of their portfolio | 1.8m $24.3m | New |
| CITADEL ADVISORS LLC 0.01% of their portfolio | 1.7m $23.2m | Added +237.7k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 1.6m $22.7m | Reduced -261.5k |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 1.5m $20.2m | Added +384.2k |
| Hood River Capital Management LLC 0.14% of their portfolio | 1.4m $19.6m | Added +463.4k |
| RENAISSANCE TECHNOLOGIES LLC 0.03% of their portfolio | 1.4m $19.5m | Added +1.0m |
| Driehaus Capital Management LLC 0.11% of their portfolio | 1.3m $18.6m | Reduced -2.4m |
| Baird Financial Group, Inc. 0.03% of their portfolio | 1.3m $18.4m | Reduced -260.2k |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND 0.02% of their portfolio | 1.2m $17.3m | New |
| NORTHERN TRUST CORP 0.00% of their portfolio | 1.2m $17.0m | Added +207.0k |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 1.2m $16.7m | Added +172.8k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 1.2m $16.6m | Added +321.2k |
| BARCLAYS PLC 0.01% of their portfolio | 1.2m $16.4m | Added +126.0k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 1.2m $16.3m | Added +137.6k |
| Point72 Asset Management, L.P. 0.02% of their portfolio | 1.1m $15.8m | Added +1.1m |
| Qube Research & Technologies Ltd 0.02% of their portfolio | 1.1m $15.7m | Reduced -91.4k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.01% of their portfolio | 1.1m $15.2m | Added +1.0m |
| Trexquant Investment LP 0.09% of their portfolio | 1.1m $15.2m | Added +381.3k |
| FIRST TRUST ADVISORS LP 0.01% of their portfolio | 1.0m $14.4m | Added +642.8k |
| Nearwater Capital Markets, Ltd 0.25% of their portfolio | 1.0m $14.3m | New |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 989.7k $13.7m | Added +117.1k |
| Shannon River Fund Management LLC 1.04% of their portfolio | 838.9k $11.6m | New |
| TUDOR INVESTMENT CORP ET AL 0.04% of their portfolio | 747.4k $10.4m | Added +327.8k |
| IMC-Chicago, LLC 0.09% of their portfolio | 734.1k $10.2m | Added +671.4k |
| STIFEL FINANCIAL CORP 0.01% of their portfolio | 731.5k $10.1m | Reduced -1.7k |
| Stephens Investment Management Group LLC 0.11% of their portfolio | 714.3k $9.9m | Reduced -178.8k |
| D. E. Shaw & Co., Inc. 0.01% of their portfolio | 671.8k $9.3m | Reduced -403.6k |
| TimesSquare Capital Management, LLC 0.13% of their portfolio | 642.0k $8.9m | New |
| OBERWEIS ASSET MANAGEMENT INC/ 0.18% of their portfolio | 636.2k $8.8m | Added +51.2k |
| Invesco Ltd. 0.00% of their portfolio | 571.6k $7.9m | Added +72.8k |
| Wolf Hill Capital Management, LP 0.71% of their portfolio | 527.3k $7.3m | Reduced -275.7k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.01% of their portfolio | 523.1k $7.2m | Added +33.4k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.00% of their portfolio | 506.3k $7.0m | Reduced -1.5m |
| OPPENHEIMER & CO INC 0.07% of their portfolio | 504.7k $7.0m | Added +92.2k |
| DNB Asset Management AS 0.02% of their portfolio | 492.0k $6.8m | Added +338.9k |
| POLEN CAPITAL MANAGEMENT LLC 0.06% of their portfolio | 465.6k $6.5m | Added +43.5k |
| SEI INVESTMENTS CO 0.01% of their portfolio | 443.2k $6.1m | Reduced -135.9k |
| FEDERATED HERMES, INC. 0.01% of their portfolio | 428.7k $5.9m | Added +258.9k |
| ALGERT GLOBAL LLC 0.07% of their portfolio | 424.8k $5.9m | Added +209.5k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 417.4k $5.8m | Added +118.5k |
| HighTower Advisors, LLC 0.01% of their portfolio | 416.4k $5.8m | Added +405.4k |
| Nuveen, LLC 0.00% of their portfolio | 397.8k $5.5m | Added +153.9k |
| ZEVENBERGEN CAPITAL INVESTMENTS LLC 0.12% of their portfolio | 381.4k $5.3m | Added +144.5k |
| Palisades Investment Partners, LLC 1.45% of their portfolio | 368.5k $5.1m | Reduced -1.0k |
| Sender Co & Partners, Inc. 2.08% of their portfolio | 355.7k $4.9m | Added +176.4k |
| Allspring Global Investments Holdings, LLC 0.01% of their portfolio | 346.0k $4.7m | Reduced -85.4k |
| WELLINGTON MANAGEMENT GROUP LLP 0.00% of their portfolio | 342.8k $4.8m | New |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 327.8k $4.5m | Added +62.4k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.03% of their portfolio | 305.6k $4.2m | Reduced -14.3k |
| CANTOR FITZGERALD, L. P. 0.04% of their portfolio | 295.8k $4.1m | New |
| SG Americas Securities, LLC 0.00% of their portfolio | 288.4k $4.0m | Reduced -134.7k |
| ESSEX INVESTMENT MANAGEMENT CO LLC 0.52% of their portfolio | 284.6k $3.9m | Reduced -160.8k |
| CREDIT AGRICOLE S A 0.01% of their portfolio | 265.2k $3.7m | New |
| HSBC HOLDINGS PLC 0.00% of their portfolio | 259.5k $3.6m | New |
| Swiss National Bank 0.00% of their portfolio | 247.5k $3.4m | Added +15.1k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 220.1k $3.1m | Reduced -5.1k |
| GROUP ONE TRADING LLC 0.09% of their portfolio | 213.3k $3.0m | New |
| Voleon Capital Management LP 0.05% of their portfolio | 205.3k $2.8m | Reduced -93.0k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 203.0k $2.8m | Reduced -340.5k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 197.8k $2.7m | Added +105.9k |
| Amundi 0.00% of their portfolio | 196.8k $2.7m | Added +32.2k |
| BLAIR WILLIAM & CO/IL 0.01% of their portfolio | 194.7k $2.7m | Added +68.1k |
| Aquatic Capital Management LLC 0.09% of their portfolio | 189.2k $2.6m | Reduced -93.4k |
| HITE Hedge Asset Management LLC 0.14% of their portfolio | 186.4k $2.6m | Added +151.1k |
| ALPS ADVISORS INC 0.01% of their portfolio | 184.5k $2.6m | Added +17.1k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 184.2k $2.6m | Added +18.6k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 183.6k $2.5m | Reduced -102.9k |
| XTX Topco Ltd 0.03% of their portfolio | 180.2k $2.5m | Added +80.8k |
| ExodusPoint Capital Management, LP 0.02% of their portfolio | 179.3k $2.5m | New |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 173.2k $2.4m | Added +35.4k |
| Huntleigh Advisors, Inc. 0.33% of their portfolio | 171.0k $2.4m | Added +8.1k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 168.0k $2.3m | Added +35.9k |
| VOYA INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 158.7k $2.2m | Added +113.3k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 152.1k $2.6m | Added +43.8k |
| Janney Montgomery Scott LLC 0.00% of their portfolio | 150.6k $2.1m | Added +5.4k |
| LPL Financial LLC 0.00% of their portfolio | 147.2k $2.0m | Added +12.5k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 141.3k $2.0m | Reduced -18.6k |
| MARSHALL WACE, LLP 0.00% of their portfolio | 131.2k $1.8m | Reduced -1.1m |
| Marex Group Ltd 0.01% of their portfolio | 126.9k $1.8m | Added +87.2k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 123.4k $1.7m | Reduced -1.1m |
| Clear Street Group Inc. 0.01% of their portfolio | 122.5k $1.7m | New |
| CANADA PENSION PLAN INVESTMENT BOARD 0.00% of their portfolio | 119.6k $1.7m | New |
| Foundations Investment Advisors, LLC 0.02% of their portfolio | 119.5k $1.7m | Added +17.6k |
| Legato Capital Management LLC 0.14% of their portfolio | 118.8k $1.6m | Reduced -109.7k |
| SLT Holdings LLC 1.04% of their portfolio | 117.8k $1.6m | Added +16.7k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 115.3k $1.6m | Added +13.4k |
| Lisanti Capital Growth, LLC 0.35% of their portfolio | 113.7k $1.6m | Reduced -238.7k |
| Cambridge Investment Research Advisors, Inc. 0.00% of their portfolio | 110.2k $1.5m | Added +70.5k |
| NOMURA HOLDINGS INC 0.01% of their portfolio | 109.8k $1.5m | New |
| Legal & General Group Plc 0.00% of their portfolio | 107.9k $1.5m | Added +21.1k |