Amprius Technologies, Inc. (AMPX) Ownership
AMPX ownership summary
as of October 17, 2026- Institutions
- 69.5% of shares outstanding
- Insiders
- 1.18% of shares outstanding
- Shares outstanding
- 146.1M
- Float
- 142.9M shares available to trade
- Short interest
- 15.85% 22.8M shares short
- Days to cover
- 4.38 short interest down 1.5% vs prior month
- Institutions 69.46%
- Insiders 1.18%
- Other investors 29.36%
AMPX top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 7.76% | 11.3M | $87.4M | +2.1M (+22.9%) | June 30, 2026 |
| 2 | Vanguard Capital Management, LLC | 3.81% | 5.6M | $42.9M | +654,110 (+13.3%) | June 30, 2026 |
| 3 | Morgan Stanley - Brokerage Accounts | 3.50% | 5.1M | $39.4M | +1.9M (+61.5%) | June 30, 2026 |
| 4 | Two Sigma Investments LLC | 2.96% | 4.3M | $33.3M | +812,555 (+23.2%) | June 30, 2026 |
| 5 | UBS Group AG | 2.79% | 4.1M | $31.4M | +1.8M (+76.2%) | June 30, 2026 |
| 6 | Geode Capital Management, LLC | 2.41% | 3.5M | $27.1M | +706,125 (+25.1%) | June 30, 2026 |
| 7 | Jane Street Group LLC | 2.33% | 3.4M | $26.2M | −759,585 (−18.3%) | June 30, 2026 |
| 8 | State Street Corp | 2.22% | 3.2M | $25.0M | +527,655 (+19.5%) | June 30, 2026 |
| 9 | The Goldman Sachs Group Inc | 1.74% | 2.5M | $19.6M | +316,113 (+14.2%) | June 30, 2026 |
| 10 | Jupiter Asset Management Limited | 1.46% | 2.1M | $16.4M | +2.1M (0.0%) | June 30, 2026 |
| 11 | LMR Partners LLP | 1.20% | 1.8M | $13.5M | +1.8M (0.0%) | June 30, 2026 |
| 12 | Citadel Advisors Llc | 1.15% | 1.7M | $12.9M | +237,684 (+16.5%) | June 30, 2026 |
| 13 | T. Rowe Price Associates, Inc. | 1.12% | 1.6M | $12.6M | −261,537 (−13.8%) | June 30, 2026 |
| 14 | Vanguard Portfolio Management, LLC | 1.00% | 1.5M | $11.2M | +384,233 (+35.8%) | June 30, 2026 |
| 15 | Hood River Capital Management LLC | 0.97% | 1.4M | $10.9M | +463,369 (+48.8%) | June 30, 2026 |
| 16 | Renaissance Technologies Corp | 0.96% | 1.4M | $10.9M | +1.0M (+291.9%) | June 30, 2026 |
| 17 | Driehaus Capital Management LLC | 0.92% | 1.3M | $10.4M | −2.4M (−64.5%) | June 30, 2026 |
| 18 | Baird Financial Group, Inc. | 0.91% | 1.3M | $10.2M | −260,189 (−16.4%) | June 30, 2026 |
| 19 | HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | 0.85% | 1.2M | $9.6M | +1.2M (0.0%) | June 30, 2026 |
| 20 | Northern Trust Corp | 0.84% | 1.2M | $9.5M | +207,003 (+20.2%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 16 holders added 16.3M shares and 4 cut 3.7M.
AMPX top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 2.62% | 3.8M | $29.5M | — | August 31, 2026 |
| 2 | iShares Russell 2000 ETF | 2.44% | 3.6M | $27.5M | −41,088 (−1.1%) | September 30, 2026 |
| 3 | Jupiter Merian Glb Eq Abs Rt I USD Acc | 1.27% | 1.9M | $14.3M | +1.9M (0.0%) | June 30, 2026 |
| 4 | Fidelity Small Cap Index | 1.03% | 1.5M | $11.6M | +12,970 (+0.9%) | July 31, 2026 |
| 5 | iShares Russell 2000 Growth ETF | 0.88% | 1.3M | $9.9M | −1,624 (−0.1%) | September 30, 2026 |
| 6 | Xtrackers MSCI USA Swap ETF 1C | 0.68% | 994K | $7.7M | −4,675 (−0.5%) | December 31, 2025 |
| 7 | T. Rowe Price New Horizons | 0.65% | 949K | $7.3M | −409 (−0.0%) | August 31, 2026 |
| 8 | Xtrackers S&P 500 Swap ETF 1C | 0.58% | 854K | $6.6M | −143,360 (−14.4%) | December 31, 2025 |
| 9 | DNB Fund Disrpt Opps A EUR Acc | 0.56% | 819K | $6.3M | +122,466 (+17.6%) | August 31, 2026 |
| 10 | Vanguard Russell 2000 ETF | 0.54% | 790K | $6.1M | +19,248 (+2.5%) | August 31, 2026 |
| 11 | Schwab US Small-Cap ETF™ | 0.53% | 773K | $6.0M | +522 (+0.1%) | September 30, 2026 |
| 12 | Fidelity Extended Market Index | 0.47% | 693K | $5.3M | −4,728 (−0.7%) | August 31, 2026 |
| 13 | Bridge Builder Small/Mid Cap Value | 0.46% | 666K | $5.1M | +666,200 (0.0%) | September 30, 2026 |
| 14 | Oberweis Micro-Cap | 0.42% | 614K | $4.7M | +52,200 (+9.3%) | June 30, 2026 |
| 15 | First Trust Small Cap Gr AlphaDEX® ETF | 0.38% | 555K | $4.3M | +980 (+0.2%) | September 30, 2026 |
| 16 | MFS New Discovery I | 0.38% | 548K | $4.2M | +178,456 (+48.3%) | August 31, 2026 |
| 17 | Invesco WilderHill Clean Energy ETF | 0.34% | 501K | $3.9M | +65,113 (+14.9%) | September 30, 2026 |
| 18 | Hood River New Opportunities Inst | 0.31% | 448K | $3.5M | +145,968 (+48.3%) | June 30, 2026 |
| 19 | American Beacon Stephens Sm Cp Gr Inv | 0.30% | 443K | $3.4M | +91,075 (+25.9%) | August 31, 2026 |
| 20 | Global X Atnms & Elctrc Vhcls ETF | 0.25% | 365K | $2.8M | +3,015 (+0.8%) | September 30, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
AMPX insider transactions
latest 20| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-04-01 | Kang Sun | Sell | $15.91 | 1,500,000 | $23.9M |
| 2026-03-23 | Kang Sun | Sell | $18.80 | 217,869 | $4.1M |
| 2026-03-12 | Steven Chu | Sell | $18.50 | 155,565 | $2.9M |
| 2026-03-12 | Wen Hsuan Hsieh | Sell | $18.44 | 413,146 | $7.6M |
| 2026-03-10 | Steven Chu | Sell | $17.92 | 166,632 | $3.0M |
| 2026-02-23 | Constantin Ionel Stefan | Sell | $10.16 | 25,366 | $257,719 |
| 2026-02-23 | Kang Sun | Sell | $10.16 | 61,251 | $622,310 |
| 2026-01-28 | Constantin Ionel Stefan | Sell | $12.00 | 39,690 | $476,280 |
| 2026-01-23 | Constantin Ionel Stefan | Sell | $12.00 | 1,600 | $19,200 |
| 2026-01-22 | Constantin Ionel Stefan | Sell | $12.04 | 492,827 | $5.9M |
| 2026-01-21 | Constantin Ionel Stefan | Sell | $12.00 | 73,280 | $879,360 |
| 2026-01-20 | Kang Sun | Sell | $11.03 | 43,185 | $476,331 |
| 2026-01-16 | Kang Sun | Sell | $11.07 | 950,548 | $10.5M |
| 2026-01-12 | Kang Sun | Sell | $10.10 | 506,267 | $5.1M |
| 2025-12-11 | Constantin Ionel Stefan | Sell | $10.51 | 198,255 | $2.1M |
| 2025-11-21 | Constantin Ionel Stefan | Sell | $10.08 | 25,024 | $252,242 |
| 2025-11-21 | Kang Sun | Sell | $10.08 | 68,655 | $692,042 |
| 2025-11-17 | Kang Sun | Sell | $10.60 | 1,000,000 | $10.6M |
| 2025-08-21 | Constantin Ionel Stefan | Sell | $6.82 | 19,159 | $130,664 |
| 2025-08-21 | Kang Sun | Sell | $6.82 | 65,654 | $447,760 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
AMPX shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns AMPX
Institutional investors own 69.5% of Amprius Technologies's shares and insiders 1.18%. The largest holder is BlackRock Inc with 7.76% of the shares (11.3M), as of June 30, 2026. Among the top 20 institutions, 16 added shares and 4 reduced their stake in the latest filings. Short interest is 15.85% of the float, or 4.38 days of average trading volume. The share count rose 193.5% since 2020.
Related: AMPX analyst forecast, AMPX key metrics. See the AMPX stock overview for the latest quote and news.
AMPX ownership FAQ
Who owns the most Amprius Technologies stock?
The largest shareholders of Amprius Technologies are BlackRock Inc (7.76%), Vanguard Capital Management, LLC (3.81%), Morgan Stanley - Brokerage Accounts (3.50%), Two Sigma Investments LLC (2.96%), UBS Group AG (2.79%).
What percentage of Amprius Technologies is owned by institutions?
Institutions hold 69.5% of Amprius Technologies's shares outstanding; insiders hold 1.18%.
Which funds own Amprius Technologies?
The largest fund holders of Amprius Technologies are Vanguard MStar Total Stk Mkt Idx Invest (2.62%), iShares Russell 2000 ETF (2.44%), Jupiter Merian Glb Eq Abs Rt I USD Acc (1.27%), Fidelity Small Cap Index (1.03%), iShares Russell 2000 Growth ETF (0.88%).
What is Amprius Technologies's short interest?
22.8M shares of Amprius Technologies were sold short, 15.85% of the float; at the average daily volume it would take 4.38 days to cover.
Are insiders buying or selling Amprius Technologies?
Of the latest 20 reported insider transactions in Amprius Technologies (since August 21, 2025), 0 were purchases and 20 were sales.
How many shares of Amprius Technologies are outstanding?
Amprius Technologies has 146.1M shares outstanding, of which 142.9M are in the public float.