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 ($5.2m this quarter). Holder counts are more reliable. Shares outstanding: 141.6m as of 2026-05-01, 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 ≈ $16.82. Options: 15 managers hold calls ($219.9m notional), 16 hold puts ($122.7m).
Trends to Q1 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 |
Buyers vs sellers
Managers adding to or starting a position, vs cutting or selling out
Numbers
| Quarter | Bought or added | Cut or sold out |
|---|---|---|
| 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 |
| Q1 2026 | 167 | 92 |
Calls vs puts
Options held, notional value, last 4 quarters. P/C = puts ÷ calls
Numbers
| Quarter | Calls | Puts | P/C |
|---|---|---|---|
| Q2 2025 | $9.6m | $934.2k | 0.10 |
| Q3 2025 | $60.3m | $12.9m | 0.21 |
| Q4 2025 | $57.6m | $20.5m | 0.36 |
| Q1 2026 | $219.9m | $122.7m | 0.56 |
Biggest buyers
| JANE STREET GROUP, LLC | Added | +3.9m |
| TWO SIGMA INVESTMENTS, LP | Added | +2.1m |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ | New | +2.0m |
| PRICE T ROWE ASSOCIATES INC /MD/ | Added | +1.8m |
| Driehaus Capital Management LLC | Added | +1.4m |
| MARSHALL WACE, LLP | New | +1.2m |
| JPMORGAN CHASE & CO | Added | +1.1m |
| D. E. Shaw & Co., Inc. | New | +1.1m |
| HRT FINANCIAL LP | New | +1.0m |
| CITADEL ADVISORS LLC | Added | +983.8k |
Biggest sellers
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Reduced | -1.6m |
| Hudson Bay Capital Management LP | Sold out | -1.1m |
| DEUTSCHE BANK AG\ | Reduced | -1.1m |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC | Reduced | -1.1m |
| JUPITER ASSET MANAGEMENT LTD | Sold out | -960.9k |
| Invesco Ltd. | Reduced | -813.1k |
| Stephens Investment Management Group LLC | Reduced | -548.6k |
| TWO SIGMA ADVISERS, LP | Sold out | -479.5k |
| Point72 Asset Management, L.P. | Reduced | -465.9k |
| Artemis Investment Management LLP | Sold out | -464.0k |
Biggest calls
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $87.0m5.2m shares |
| CITADEL ADVISORS LLC | Added | $24.3m1.4m shares |
| JANE STREET GROUP, LLC | Added | $21.0m1.2m shares |
| Point72 Asset Management, L.P. | Added | $20.4m1.2m shares |
| PEAK6 LLC | Added | $18.1m1.1m shares |
| GROUP ONE TRADING LLC | Added | $16.9m1.0m shares |
| IMC-Chicago, LLC | Added | $13.6m807.6k shares |
| SIMPLEX TRADING, LLC | Reduced | $7.8m464.8k shares |
| DLD Asset Management, LP | New | $3.9m232.9k shares |
| Squarepoint Ops LLC | New | $2.9m173.9k shares |
Biggest puts
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | Added | $22.8m1.4m shares |
| CITADEL ADVISORS LLC | Added | $22.5m1.3m shares |
| JANE STREET GROUP, LLC | Added | $19.7m1.2m shares |
| PICTON MAHONEY ASSET MANAGEMENT | New | $11.0m650.0k shares |
| IMC-Chicago, LLC | Added | $9.5m563.8k shares |
| UBS Group AG | New | $8.4m500.0k shares |
| Parallax Volatility Advisers, L.P. | New | $8.3m385.0k shares |
| SIMPLEX TRADING, LLC | Added | $6.1m362.1k shares |
| GROUP ONE TRADING LLC | Added | $5.3m315.1k shares |
| Point72 Asset Management, L.P. | Added | $4.0m236.2k 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 Q1 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 |
|---|---|---|---|---|---|
| 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 | — |
| Q1 2026 | 0 | — | 4 | $41.9m | — |
| Date | Insider | Trade | Value |
|---|---|---|---|
| 2026-03-23 | Sun Kang Director · See Footnote | Sold | $4.1m217.9k shares |
| 2026-03-12 | HSIEH Wen Hsuan Director | Sold | $7.6m413.1k shares |
| 2026-03-12 | Chu Steven Director | Sold | $2.9m155.6k shares |
| 2026-03-10 | Chu Steven Director | Sold | $3.0m166.6k shares |
| 2026-02-23 | Sun Kang Director | Sold | $622.3k61.3k shares |
| 2026-02-23 | Stefan Constantin Ionel Chief Technology Officer | Sold | $257.7k25.4k shares |
| 2026-01-28 | Stefan Constantin Ionel Chief Technology Officer | Sold | $476.3k39.7k shares |
| 2026-01-23 | Stefan Constantin Ionel Chief Technology Officer | Sold | $19.2k1.6k shares |
| 2026-01-22 | Stefan Constantin Ionel Chief Technology Officer | Sold | $5.9m492.8k shares |
| 2026-01-21 | Stefan Constantin Ionel Chief Technology Officer | Sold | $879.4k73.3k shares |
| 2026-01-20 | Sun Kang Director | Sold | $476.3k43.2k shares |
| 2026-01-16 | Sun Kang Director | Sold | $10.5m950.5k shares |
| 2026-01-12 | Sun Kang Director | Sold | $5.1m506.3k 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, Q1 2026
| Manager | Shares | Change |
|---|---|---|
| BlackRock, Inc. 0.00% of their portfolio | 9.2m $155.5m | Added +401.8k |
| VANGUARD CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 4.9m $82.8m | First filing |
| JANE STREET GROUP, LLC 0.08% of their portfolio | 4.2m $70.1m | Added +3.9m |
| Driehaus Capital Management LLC 0.47% of their portfolio | 3.8m $64.0m | Added +1.4m |
| TWO SIGMA INVESTMENTS, LP 0.05% of their portfolio | 3.5m $59.1m | Added +2.1m |
| MORGAN STANLEY 0.00% of their portfolio | 3.2m $53.3m | Added +352.3k |
| GEODE CAPITAL MANAGEMENT, LLC 0.00% of their portfolio | 2.8m $47.5m | Added +136.1k |
| STATE STREET CORP 0.00% of their portfolio | 2.7m $45.7m | Added +158.9k |
| UBS Group AG 0.01% of their portfolio | 2.3m $39.0m | Added +212.6k |
| GOLDMAN SACHS GROUP INC 0.00% of their portfolio | 2.2m $37.5m | Added +31.3k |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ 0.01% of their portfolio | 2.0m $34.1m | New |
| PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio | 1.9m $32.0m | Added +1.8m |
| Baird Financial Group, Inc. 0.04% of their portfolio | 1.6m $26.7m | Added +811.7k |
| CITADEL ADVISORS LLC 0.02% of their portfolio | 1.4m $24.3m | Added +983.8k |
| MARSHALL WACE, LLP 0.02% of their portfolio | 1.2m $20.7m | New |
| Qube Research & Technologies Ltd 0.03% of their portfolio | 1.2m $20.7m | Added +353.5k |
| JPMORGAN CHASE & CO 0.00% of their portfolio | 1.2m $17.9m | Added +1.1m |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC 0.07% of their portfolio | 1.2m $19.7m | Added +185.2k |
| D. E. Shaw & Co., Inc. 0.01% of their portfolio | 1.1m $18.1m | New |
| VANGUARD PORTFOLIO MANAGEMENT LLC 0.00% of their portfolio | 1.1m $18.1m | First filing |
| BARCLAYS PLC 0.01% of their portfolio | 1.1m $17.8m | Added +585.0k |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.00% of their portfolio | 1.0m $17.5m | Added +2.5k |
| MILLENNIUM MANAGEMENT LLC 0.01% of their portfolio | 1.0m $17.5m | Reduced -50.0k |
| NORTHERN TRUST CORP 0.00% of their portfolio | 1.0m $17.2m | Added +59.5k |
| HRT FINANCIAL LP 0.06% of their portfolio | 1.0m $16.9m | New |
| Hood River Capital Management LLC 0.16% of their portfolio | 949.1k $16.0m | Added +139.4k |
| Stephens Investment Management Group LLC 0.21% of their portfolio | 893.1k $15.1m | Reduced -548.6k |
| DEUTSCHE BANK AG\ 0.00% of their portfolio | 875.0k $14.8m | Reduced -1.1m |
| VANGUARD FIDUCIARY TRUST CO 0.00% of their portfolio | 872.6k $14.7m | First filing |
| Wolf Hill Capital Management, LP 1.92% of their portfolio | 802.9k $13.5m | New |
| MYDA Advisors LLC 2.93% of their portfolio | 735.0k $12.4m | New |
| STIFEL FINANCIAL CORP 0.01% of their portfolio | 733.2k $12.4m | Reduced -38.3k |
| Trexquant Investment LP 0.09% of their portfolio | 716.3k $12.1m | Added +685.2k |
| Science & Technology Partners, L.P. 2.80% of their portfolio | 635.1k $10.7m | New |
| OBERWEIS ASSET MANAGEMENT INC/ 0.29% of their portfolio | 585.0k $9.9m | New |
| SEI INVESTMENTS CO 0.01% of their portfolio | 579.2k $9.8m | Added +147.4k |
| Russell Investments Group, Ltd. 0.01% of their portfolio | 543.5k $9.2m | Added +308.4k |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC 0.04% of their portfolio | 532.0k $9.0m | Reduced -1.1m |
| THAMES CAPITAL MANAGEMENT LLC 1.59% of their portfolio | 526.8k $8.9m | Unchanged |
| Invesco Ltd. 0.00% of their portfolio | 498.8k $8.4m | Reduced -813.1k |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.01% of their portfolio | 489.7k $8.3m | Reduced -1.2k |
| ESSEX INVESTMENT MANAGEMENT CO LLC 1.19% of their portfolio | 445.4k $7.5m | Reduced -71.3k |
| Allspring Global Investments Holdings, LLC 0.01% of their portfolio | 431.4k $6.7m | Added +377.5k |
| SG Americas Securities, LLC 0.01% of their portfolio | 423.0k $7.1m | Added +167.8k |
| POLEN CAPITAL MANAGEMENT LLC 0.05% of their portfolio | 422.1k $7.1m | Added +133.9k |
| TUDOR INVESTMENT CORP ET AL 0.04% of their portfolio | 419.7k $7.1m | New |
| OPPENHEIMER & CO INC 0.08% of their portfolio | 412.5k $7.0m | Reduced -29.6k |
| FIRST TRUST ADVISORS LP 0.00% of their portfolio | 394.6k $6.7m | Added +361.8k |
| Palisades Investment Partners, LLC 2.44% of their portfolio | 369.5k $6.2m | New |
| Calamos Advisors LLC 0.02% of their portfolio | 364.5k $6.1m | Added +245.5k |
| RENAISSANCE TECHNOLOGIES LLC 0.01% of their portfolio | 359.5k $6.1m | Added +246.7k |
| Lisanti Capital Growth, LLC 1.50% of their portfolio | 352.4k $5.9m | Added +153.5k |
| Public Sector Pension Investment Board 0.02% of their portfolio | 332.0k $5.6m | New |
| SILVERCREST ASSET MANAGEMENT GROUP LLC 0.04% of their portfolio | 319.9k $5.4m | Reduced -39.5k |
| Bank of New York Mellon Corp 0.00% of their portfolio | 298.9k $5.0m | Reduced -10.8k |
| Voleon Capital Management LP 0.11% of their portfolio | 298.4k $5.0m | Added +107.2k |
| BNP PARIBAS FINANCIAL MARKETS 0.00% of their portfolio | 286.5k $4.8m | Reduced -420.5k |
| Aquatic Capital Management LLC 0.14% of their portfolio | 282.7k $4.8m | Added +256.4k |
| BANK OF AMERICA CORP /DE/ 0.00% of their portfolio | 265.4k $4.5m | Reduced -34.5k |
| Informed Momentum Co LLC 0.51% of their portfolio | 262.0k $4.4m | Added +25.2k |
| Nuveen, LLC 0.00% of their portfolio | 243.9k $4.1m | Added +10.7k |
| ZEVENBERGEN CAPITAL INVESTMENTS LLC 0.11% of their portfolio | 236.9k $4.0m | New |
| Swiss National Bank 0.00% of their portfolio | 232.4k $3.9m | Added +10.4k |
| Squarepoint Ops LLC 0.01% of their portfolio | 232.1k $3.9m | Added +14.1k |
| Legato Capital Management LLC 0.35% of their portfolio | 228.5k $3.9m | Added +23.9k |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 0.00% of their portfolio | 227.1k $3.8m | New |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio | 225.2k $3.8m | Added +36.4k |
| ALGERT GLOBAL LLC 0.05% of their portfolio | 215.3k $3.6m | Added +82.7k |
| Sender Co & Partners, Inc. 2.21% of their portfolio | 179.2k $3.0m | New |
| FEDERATED HERMES, INC. 0.00% of their portfolio | 169.8k $2.9m | Reduced -116.9k |
| OSAIC HOLDINGS, INC. 0.00% of their portfolio | 169.5k $2.9m | Added +160.8k |
| ALPS ADVISORS INC 0.01% of their portfolio | 167.4k $2.8m | Added +20.4k |
| NEW YORK STATE COMMON RETIREMENT FUND 0.00% of their portfolio | 165.6k $2.8m | Added +136.0k |
| Amundi 0.00% of their portfolio | 164.6k $2.8m | Added +24.3k |
| Y-Intercept (Hong Kong) Ltd 0.05% of their portfolio | 164.2k $2.8m | New |
| Huntleigh Advisors, Inc. 0.47% of their portfolio | 162.9k $2.7m | Added +2.3k |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio | 159.9k $2.7m | Added +52.0k |
| DNB Asset Management AS 0.01% of their portfolio | 153.0k $2.6m | New |
| HUSSMAN STRATEGIC ADVISORS, INC. 0.54% of their portfolio | 147.0k $2.5m | Reduced -63.0k |
| Janney Montgomery Scott LLC 0.01% of their portfolio | 145.2k $2.4m | Reduced -23.2k |
| AQR CAPITAL MANAGEMENT LLC 0.00% of their portfolio | 137.7k $2.3m | Added +1.6k |
| Schonfeld Strategic Advisors LLC 0.02% of their portfolio | 135.8k $2.3m | New |
| LPL Financial LLC 0.00% of their portfolio | 134.8k $2.3m | Added +20.1k |
| RHUMBLINE ADVISERS 0.00% of their portfolio | 132.1k $2.2m | Added +6.9k |
| BLAIR WILLIAM & CO/IL 0.01% of their portfolio | 126.6k $2.1m | Added +86.5k |
| ARDSLEY ADVISORY PARTNERS LP 0.32% of their portfolio | 125.0k $2.1m | New |
| RAYMOND JAMES FINANCIAL INC 0.00% of their portfolio | 122.3k $2.1m | Reduced -102.1k |
| CenterBook Partners LP 0.11% of their portfolio | 118.3k $2.0m | New |
| ALLIANCEBERNSTEIN L.P. 0.00% of their portfolio | 108.3k $854.2k | Reduced -15.6k |
| Apis Capital Advisors, LLC 0.28% of their portfolio | 108.0k $1.8m | New |
| ROYAL BANK OF CANADA 0.00% of their portfolio | 101.9k $1.7m | Added +10.0k |
| Foundations Investment Advisors, LLC 0.02% of their portfolio | 101.9k $1.7m | Reduced -22.2k |
| SLT Holdings LLC 1.20% of their portfolio | 101.0k $1.7m | Reduced -22.2k |
| XTX Topco Ltd 0.03% of their portfolio | 99.4k $1.7m | New |
| Quantbot Technologies LP 0.07% of their portfolio | 96.6k $1.6m | New |
| FRANKLIN RESOURCES INC 0.00% of their portfolio | 94.0k $1.6m | Added +15.2k |
| WELLS FARGO & COMPANY/MN 0.00% of their portfolio | 91.9k $1.5m | Reduced -50.4k |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP 0.00% of their portfolio | 89.2k $1.5m | Reduced -1.6m |
| Legal & General Group Plc 0.00% of their portfolio | 86.9k $1.5m | Reduced -15.3k |
| VANGUARD ASSET MANAGEMENT, Ltd 0.00% of their portfolio | 83.4k $1.4m | First filing |