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 ($1.1m this quarter). Holder counts are more reliable. Shares outstanding: 130.5m as of 2025-10-30, 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 ≈ $7.89. Options: 10 managers hold calls ($57.6m notional), 10 hold puts ($20.5m).
Trends to Q4 2025
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 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| Q1 2024 | 24 | 23 |
| Q2 2024 | 43 | 13 |
| Q3 2024 | 38 | 22 |
| Q4 2024 | 61 | 21 |
| Q1 2025 | 64 | 36 |
| Q2 2025 | 84 | 38 |
| Q3 2025 | 149 | 45 |
| Q4 2025 | 129 | 81 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q1 2025 | $4.8m | $1.0m | 0.21 |
| Q2 2025 | $9.6m | $934.2k | 0.10 |
| Q3 2025 | $60.3m | $12.9m | 0.21 |
| Q4 2025 | $57.6m | $20.5m | 0.36 |
Biggest buyers
| BlackRock, Inc. | Added | +1.4m |
| Hudson Bay Capital Management LP | New | +1.1m |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC | New | +984.9k |
| Qube Research & Technologies Ltd | New | +874.1k |
| Hood River Capital Management LLC | New | +809.7k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | +786.0k |
| JUPITER ASSET MANAGEMENT LTD | Added | +761.5k |
| VANGUARD GROUP INC | Added | +616.0k |
| UBS Group AG | Added | +550.9k |
| MILLENNIUM MANAGEMENT LLC | Added | +497.4k |
Biggest sellers
| CITADEL ADVISORS LLC | Reduced | -2.1m |
| BNP PARIBAS FINANCIAL MARKETS | Reduced | -1.2m |
| Invesco Ltd. | Reduced | -1.1m |
| TUDOR INVESTMENT CORP ET AL | Sold out | -715.7k |
| Driehaus Capital Management LLC | Reduced | -697.5k |
| Capitolis Liquid Global Markets LLC | Sold out | -680.6k |
| JPMORGAN CHASE & CO | Reduced | -492.0k |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | Sold out | -471.8k |
| JANE STREET GROUP, LLC | Reduced | -463.2k |
| TWO SIGMA ADVISERS, LP | Reduced | -332.5k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $18.2m2.3m shares |
| JANE STREET GROUP, LLC | Added | $7.1m895.0k shares |
| BARCLAYS PLC | Unchanged | $5.9m750.0k shares |
| CITADEL ADVISORS LLC | Added | $5.9m746.3k shares |
| Point72 Asset Management, L.P. | New | $4.9m619.3k shares |
| GROUP ONE TRADING LLC | Reduced | $4.3m539.8k shares |
| SIMPLEX TRADING, LLC | Reduced | $4.0m511.8k shares |
| IMC-Chicago, LLC | Reduced | $3.5m443.2k shares |
| PEAK6 LLC | Added | $3.3m417.6k shares |
| CAPITAL FUND MANAGEMENT S.A. | New | $478.9k60.7k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $8.3m1.1m shares |
| CITADEL ADVISORS LLC | Added | $4.0m505.3k shares |
| IMC-Chicago, LLC | Added | $2.1m265.1k shares |
| JANE STREET GROUP, LLC | Added | $1.7m220.6k shares |
| PEAK6 LLC | New | $1.5m187.8k shares |
| FIRST SABREPOINT CAPITAL MANAGEMENT LP | Unchanged | $1.4m180.6k shares |
| Point72 Asset Management, L.P. | New | $546.8k69.3k shares |
| SIMPLEX TRADING, LLC | Reduced | $493.1k62.5k shares |
| GROUP ONE TRADING LLC | Reduced | $411.9k52.2k shares |
| JPMORGAN CHASE & CO | Reduced | $1.6k200 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 in Q4 2025
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 |
|---|---|---|---|---|---|
| Q1 2024 | 0 | — | 1 | $1.8m | $1.8m |
| Q2 2024 | 0 | — | 5 | $1.4m | $299.8k |
| Q3 2024 | 0 | — | 5 | $724.5k | — |
| 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 | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2025-12-11 | Stefan Constantin Ionel Chief Technology Officer | Sold | $2.1m198.3k shares |
| 2025-11-21 | Sun Kang Chief Executive Officer, director | Sold | $692.0k68.7k shares |
| 2025-11-21 | Stefan Constantin Ionel Chief Technology Officer | Sold | $252.2k25.0k shares |
| 2025-11-17 | Sun Kang Chief Executive Officer, director | Sold | $10.6m1.0m 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, Q4 2025
| Manager | Shares | Change |
|---|---|---|
| BlackRock, Inc. 0.00% of their portfolio | 8.8m $69.6m | Added +1.4m |
| VANGUARD GROUP INC 0.00% of their portfolio | 7.1m $56.2m | Added +616.0k |
| MORGAN STANLEY 0.00% of their portfolio | 2.8m $22.2m | Added +66.1k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 2.7m $21.1m | Added +253.5k |
| STATE STREET CORP 0.00% of their portfolio | 2.6m $20.1m | Added +363.9k |
| Driehaus Capital Management LLC 0.13% of their portfolio | 2.4m $18.9m | Reduced -697.5k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 2.2m $17.3m | Added +410.7k |
| UBS Group AG 0.00% of their portfolio | 2.1m $16.6m | Added +550.9k |
| DEUTSCHE BANK AG\ 0.01% of their portfolio | 2.0m $15.4m | Reduced -111.5k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.02% of their portfolio | 1.7m $13.3m | Added +786.0k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.04% of their portfolio | 1.6m $12.6m | Reduced -274.1k |
| Stephens Investment Management Group LLC 0.15% of their portfolio | 1.4m $11.4m | Added +358.8k |
| TWO SIGMA INVESTMENTS, LP 0.02% of their portfolio | 1.4m $11.3m | Reduced -316.6k |
| Invesco Ltd. 0.00% of their portfolio | 1.3m $10.4m | Reduced -1.1m |
| NORGES BANK 0.00% of their portfolio | 1.3m $10.3m | Not comparable |
| Hudson Bay Capital Management LP 0.05% of their portfolio | 1.1m $8.7m | New |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 1.1m $8.6m | Added +497.4k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 1.0m $8.2m | Added +62.4k |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC 0.02% of their portfolio | 984.9k $7.8m | New |
| NORTHERN TRUST CORP 0.00% of their portfolio | 963.2k $7.6m | Added +110.9k |
| JUPITER ASSET MANAGEMENT LTD 0.06% of their portfolio | 960.9k $7.6m | Added +761.5k |
| Qube Research & Technologies Ltd 0.01% of their portfolio | 874.1k $6.9m | New |
| Hood River Capital Management LLC 0.07% of their portfolio | 809.7k $6.4m | New |
| Baird Financial Group, Inc. 0.01% of their portfolio | 773.4k $6.1m | Reduced -103.5k |
| STIFEL FINANCIAL CORP 0.01% of their portfolio | 771.5k $6.1m | Reduced -24.3k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 707.1k $5.6m | Reduced -1.2m |
| THAMES CAPITAL MANAGEMENT LLC 0.60% of their portfolio | 526.8k $4.2m | Unchanged |
| ESSEX INVESTMENT MANAGEMENT CO LLC 0.62% of their portfolio | 516.8k $4.1m | Reduced -180.6k |
| Point72 Asset Management, L.P. 0.01% of their portfolio | 493.9k $3.9m | Added +459.9k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.01% of their portfolio | 490.9k $3.9m | Reduced -19.6k |
| TWO SIGMA ADVISERS, LP 0.01% of their portfolio | 479.5k $3.8m | Reduced -332.5k |
| BARCLAYS PLC 0.00% of their portfolio | 469.9k $3.7m | Added +336.6k |
| Artemis Investment Management LLP 0.04% of their portfolio | 464.0k $3.7m | Reduced -14.5k |
| CITADEL ADVISORS LLC 0.00% of their portfolio | 454.9k $3.6m | Reduced -2.1m |
| OSTERWEIS CAPITAL MANAGEMENT INC 0.15% of their portfolio | 454.8k $3.6m | Added +267.4k |
| OPPENHEIMER & CO INC 0.05% of their portfolio | 442.1k $3.5m | Added +142.8k |
| SEI INVESTMENTS CO 0.00% of their portfolio | 431.8k $3.4m | Added +353.1k |
| Engineers Gate Manager LP 0.03% of their portfolio | 360.4k $2.8m | Added +171.6k |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.02% of their portfolio | 359.4k $2.8m | New |
| Bank of New York Mellon Corp 0.00% of their portfolio | 309.7k $2.4m | Added +17.8k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 299.9k $2.4m | Added +9.5k |
| Verition Fund Management LLC 0.01% of their portfolio | 292.1k $2.3m | Reduced -31.3k |
| POLEN CAPITAL MANAGEMENT LLC 0.01% of their portfolio | 288.3k $2.3m | Reduced -51.1k |
| FEDERATED HERMES, INC. 0.00% of their portfolio | 286.7k $2.3m | Added +194.9k |
| Walleye Capital LLC 0.01% of their portfolio | 269.4k $2.1m | Added +138.6k |
| SG Americas Securities, LLC 0.00% of their portfolio | 255.3k $2.0m | New |
| Informed Momentum Co LLC 0.21% of their portfolio | 236.8k $1.9m | Reduced -251.7k |
| Russell Investments Group, Ltd. 0.00% of their portfolio | 235.0k $1.9m | Reduced -70.1k |
| Nuveen, LLC 0.00% of their portfolio | 233.2k $1.8m | Reduced -9.1k |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 224.4k $1.8m | Reduced -15.5k |
| Swiss National Bank 0.00% of their portfolio | 222.0k $1.8m | Added +46.7k |
| Squarepoint Ops LLC 0.00% of their portfolio | 218.0k $1.7m | Added +160.4k |
| JANE STREET GROUP, LLC 0.00% of their portfolio | 213.4k $1.7m | Reduced -463.2k |
| HUSSMAN STRATEGIC ADVISORS, INC. 0.40% of their portfolio | 210.0k $1.7m | New |
| Legato Capital Management LLC 0.14% of their portfolio | 204.6k $1.6m | Reduced -46.6k |
| Lisanti Capital Growth, LLC 0.37% of their portfolio | 198.9k $1.6m | Reduced -66.8k |
| Voleon Capital Management LP 0.03% of their portfolio | 191.2k $1.5m | Added +157.7k |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 188.8k $1.5m | Added +72.4k |
| Janney Montgomery Scott LLC 0.00% of their portfolio | 168.5k $1.3m | Reduced -115.0k |
| Huntleigh Advisors, Inc. 0.21% of their portfolio | 160.6k $1.3m | Added +4.5k |
| ALPS ADVISORS INC 0.01% of their portfolio | 147.1k $1.2m | Reduced -1.7k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 142.4k $1.1m | Added +83.6k |
| Amundi 0.00% of their portfolio | 140.3k $1.1m | New |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 136.1k $1.1m | Added +4.6k |
| ALGERT GLOBAL LLC 0.02% of their portfolio | 132.7k $1.0m | Reduced -250.4k |
| Alberta Investment Management Corp 0.01% of their portfolio | 126.9k $1.0m | New |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 125.2k $987.5k | Reduced -4.8k |
| Foundations Investment Advisors, LLC 0.01% of their portfolio | 124.1k $979.4k | Added +3.0k |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 123.9k $977.3k | Unchanged |
| SLT Holdings LLC 0.65% of their portfolio | 123.3k $972.8k | Added +3.0k |
| Calamos Advisors LLC 0.00% of their portfolio | 119.0k $939.2k | Reduced -52.0k |
| MANGROVE PARTNERS IM, LLC 0.07% of their portfolio | 116.6k $920.2k | New |
| LPL Financial LLC 0.00% of their portfolio | 114.7k $905.0k | Reduced -50.7k |
| RENAISSANCE TECHNOLOGIES LLC 0.00% of their portfolio | 112.8k $890.2k | Added +100.4k |
| BOOTHBAY FUND MANAGEMENT, LLC 0.02% of their portfolio | 112.3k $886.2k | Added +96.2k |
| CAPITAL FUND MANAGEMENT S.A. 0.01% of their portfolio | 109.0k $860.2k | Reduced -22.4k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 107.9k $851.6k | Added +24.3k |
| Legal & General Group Plc 0.00% of their portfolio | 102.2k $806.1k | Added +14.8k |
| Faithward Advisors, LLC 0.12% of their portfolio | 101.2k $798.3k | New |
| GSA CAPITAL PARTNERS LLP 0.07% of their portfolio | 96.7k $763.0k | Reduced -4.4k |
| Numerai GP LLC 0.09% of their portfolio | 96.2k $759.1k | Added +21.7k |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 91.9k $726.0k | Reduced -35.5k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 83.4k $658.4k | Reduced -492.0k |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 80.6k $636.0k | Added +31.5k |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 78.8k $622.0k | New |
| Polar Asset Management Partners Inc. 0.01% of their portfolio | 78.6k $620.2k | New |
| AMERIPRISE FINANCIAL INC 0.00% of their portfolio | 78.0k $615.5k | Added +45.0k |
| FOX RUN MANAGEMENT, L.L.C. 0.09% of their portfolio | 74.8k $590.0k | Added +42.3k |
| CITIGROUP INC 0.00% of their portfolio | 74.8k $589.9k | Reduced -22.0k |
| CoreCommodity Management, LLC 0.12% of their portfolio | 74.0k $584.0k | Added +35.3k |
| DARK FOREST CAPITAL MANAGEMENT LP 0.03% of their portfolio | 71.9k $567.2k | Added +51.8k |
| Granahan Investment Management, LLC 0.02% of their portfolio | 64.4k $508.0k | New |
| MetLife Investment Management, LLC 0.00% of their portfolio | 60.5k $477.4k | Added +2.3k |
| Inspire Investing, LLC 0.04% of their portfolio | 60.2k $475.3k | Added +16.4k |
| HITE Hedge Asset Management LLC 0.03% of their portfolio | 57.8k $456.1k | Unchanged |
| Mirae Asset Global Investments Co., Ltd. 0.00% of their portfolio | 56.1k $442.6k | Reduced -2.3k |
| CANADA PENSION PLAN INVESTMENT BOARD 0.00% of their portfolio | 55.1k $434.7k | New |
| Allspring Global Investments Holdings, LLC 0.00% of their portfolio | 53.9k $471.2k | Added +4.8k |
| INTECH INVESTMENT MANAGEMENT LLC 0.00% of their portfolio | 51.1k $403.3k | Added +12.9k |
| B. Riley Wealth Advisors, Inc. 0.02% of their portfolio | 50.2k $396.1k | Reduced -500 |