Stocks › AMPX
Amprius Technologies AMPX
US equityMarket cap rank #3054
$8.72 +$1.20 (+15.96%)
Market closed · Nov 7, 9:10 am ET · Last extended-hours $8.66 -0.69%
Open$7.85
Prev close$7.52
Day range$7.71 – $8.82
Volume6.10M
Market cap$1.27B
P/E (TTM)–
Dividend yield–
Ownership & positioning
Who holds it, who is betting against it, and where the big money is moving
Institutional ownership74.4%-3.87 pts vs. prior quarter
Institutions holding318+1 vs. prior quarter
Insider trades (recent)12 buys / 38 sellsNet selling
Short interest15.56% of floatDays to cover 3.8 · as of 15 Oct 2026
Short-sale volume share23.0%5-day average of daily volume
Short-sale volume as % of daily volume
Large-order net flow, last 20 sessions
Net of large-order buying minus selling, in USD. Over this window: −$4.65M (7 inflow days, 13 outflow days).
Net flow by order size, last 20 sessions
Super/Big orders approximate institutional-size trades; Mid/Small approximate retail-size trades. Net buy minus sell value in each bucket, summed over the window.
The five largest holders on file together own 21.6% of shares outstanding.
Largest holders
By investor type
Reported short interest has fallen from 16.90% to 15.56% of float over the last 6 biweekly reports (31 Jul 2026 to 15 Oct 2026).
Recent institutional activity
| Holder | Type | Period | Share change | New stake |
|---|---|---|---|---|
| Jupiter Fund Management Plc | Mutual Fund | 2026/Q3 | +2,133,397 | 1.5% |
| BlackRock | Mutual Fund | 2026/Q3 | +2,109,481 | 7.8% |
| Morgan Stanley | Public Company | 2026/Q3 | +1,938,931 | 3.5% |
| UBS Asset Management | Mutual Fund | 2026/Q3 | +1,755,594 | 2.9% |
| LMR Partners LLP | Hedge Fund | 2026/Q3 | +1,750,850 | 1.2% |
| Healthcare of Ontario Pension Plan Trust Fund | Government Pension Fund | 2026/Q3 | +1,248,700 | 0.9% |
| Point72 Asset Management, L.P. | Hedge Fund | 2026/Q3 | +1,111,890 | 0.8% |
| Renaissance Technologies Corp. | Hedge Fund | 2026/Q3 | +1,049,400 | 1.0% |
| Nearwater Capital Markets, Limited | Private Company | 2026/Q3 | +1,034,700 | 0.7% |
| Susquehanna International Group, LLP | Private Company | 2026/Q3 | +1,011,099 | 0.8% |
| Shannon River Fund Management, LLC | Hedge Fund | 2026/Q3 | +838,887 | 0.6% |
| Two Sigma Investments, LP | Hedge Fund | 2026/Q3 | +812,555 | 3.0% |
| Vanguard Capital Management, LLC | Mutual Fund | 2026/Q3 | +771,219 | 4.5% |
| Geode Capital Management, LLC | Mutual Fund | 2026/Q3 | +706,125 | 2.4% |
| IMC Trading B.V. | Private Company | 2026/Q3 | +671,435 | 0.5% |
Institutional buy/sell activity by reporting period, largest moves first.
Insider transactions
| Date | Insider | Title | Transaction | Shares | Price | Held after |
|---|---|---|---|---|---|---|
| 24 Aug 2026 | Thomas Stepien | Chief Executive Officer | Other Acquisition | +346 | – | 47,260 |
| 24 Aug 2026 | Thomas Stepien | Chief Executive Officer | Other Disposition | -15,346 | – | 47,260 |
| 23 Aug 2026 | Thomas Stepien | Chief Executive Officer | Intent to Sell (Form 144) | -8,000 | $10.03 | – |
| 23 Aug 2026 | Thomas Stepien | Chief Executive Officer | Open Market Disposition | -31,529 | $10.34 | 47,260 |
| 20 Aug 2026 | Kang Sun | Executive Advisor & Director | Open Market Disposition | -62,101 | $10.34 | 363,115 |
| 20 Aug 2026 | Constantin Stefan | Chief Technology Officer | Open Market Disposition | -29,681 | $10.34 | 246,453 |
| 14 Jun 2026 | Donald Dixon | Independent Chairperson | Open Market Disposition | -85,000 | $17.17 | 792,178 |
| 11 Jun 2026 | Donald Dixon | Independent Chairperson | Other Acquisition | +10,423 | – | 10,423 |
| 11 Jun 2026 | Kathleen Bayless | Independent Director | Other Acquisition | +10,423 | – | 10,423 |
| 11 Jun 2026 | Livingston Satterthwaite | Member of Industry Advisory Council & Independent Director | Other Acquisition | +10,423 | – | 199,102 |
| 11 Jun 2026 | Steven Chu | Independent Director | Other Acquisition | +10,423 | – | 10,423 |
| 8 Jun 2026 | Donald Dixon | Independent Chairperson | Open Market Disposition | -40,000 | $19.13 | 832,734 |
| 7 Jun 2026 | Donald Dixon | Independent Chairperson | Intent to Sell (Form 144) | -125,000 | $18.85 | – |
| 3 Jun 2026 | Thomas Stepien | Chief Executive Officer | Other Acquisition | +36,914 | – | 46,914 |
| 3 Jun 2026 | Thomas Stepien | Chief Executive Officer | Other Disposition | -67,298 | – | 46,914 |
| 3 Jun 2026 | Thomas Stepien | Chief Executive Officer | Open Market Disposition | -2,000 | $20.97 | 46,914 |
| 26 May 2026 | Kang Sun | Executive Advisor & Director | Open Market Disposition | -356 | $17.19 | 298,242 |
| 26 May 2026 | Thomas Stepien | Chief Executive Officer | Open Market Disposition | -4,375 | $17.19 | 79,298 |
| 26 May 2026 | Constantin Stefan | Chief Technology Officer | Open Market Disposition | -3,208 | $17.19 | 217,002 |
| 25 May 2026 | Donald Dixon | Independent Chairperson | Open Market Disposition | -17,895 | $17.90 | 872,734 |
From Form 4/Form 144 filings. Negative share counts are disposals (sales, gifts, or shares withheld for taxes); positive are acquisitions.
Short interest, by report
| Report date | Shares short | % of float | Days to cover |
|---|---|---|---|
| 15 Oct 2026 | 22,724,816 | 15.6% | 3.8 |
| 30 Sep 2026 | 22,815,859 | 15.6% | 3.8 |
| 15 Sep 2026 | 22,685,478 | 15.5% | 5.1 |
| 31 Aug 2026 | 23,159,125 | 15.9% | 5.3 |
| 14 Aug 2026 | 22,146,891 | 15.2% | 3.1 |
| 31 Jul 2026 | 23,928,102 | 16.9% | 4.2 |
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