Amprius Technologies Inc.
Ownership
Ownership Structure
Who owns Amprius Technologies Inc. (AMPX)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 97.8% of the shares are freely tradable; institutional investors hold 65.2%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 7.76 | 11,335,092 | +22.9 | 06/30/2026 |
| Vanguard Capital Management, LLC | 3.81 | 5,562,985 | +13.3 | 06/30/2026 |
| Morgan Stanley - Brokerage Accounts | 3.50 | 5,105,505 | +61.5 | 06/30/2026 |
| Two Sigma Investments LLC | 2.96 | 4,318,630 | +23.2 | 06/30/2026 |
| UBS Group AG | 2.79 | 4,072,269 | +76.2 | 06/30/2026 |
| Geode Capital Management, LLC | 2.41 | 3,520,655 | +25.1 | 06/30/2026 |
| Jane Street Group LLC | 2.33 | 3,401,071 | -18.3 | 06/30/2026 |
| State Street Corp | 2.22 | 3,240,285 | +19.5 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 2.98 | 4,350,605 | +13.8 | 09/30/2026 |
| iShares Russell 2000 ETF | 2.44 | 3,562,533 | -1.1 | 09/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Sun Kang | Director | 1,218,397 | 10,478,214 $ | Aug 21, 2026 | direct |
| Stefan Constantin Ionel | Chief Technology Officer | 771,629 | 6,636,009 $ | Aug 21, 2026 | direct |
| Stepien Thomas M | Chief Executive Officer | 616,010 | 5,297,686 $ | Aug 25, 2026 | both |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Aug 25, 2026 | Stepien Thomas M | Chief Executive Officer | Other | 346 | 0.00 | – |
| Aug 25, 2026 | Stepien Thomas M | Chief Executive Officer | Other | 346 | 0.00 | – |
| Aug 25, 2026 | Stepien Thomas M | Chief Executive Officer | Other | 5,000 | 0.00 | – |
| Aug 24, 2026 | Stepien Thomas M | Chief Executive Officer | Sell | 8,000 | 10.03 | 80,240 |
| Aug 21, 2026 | Stepien Thomas M | Chief Executive Officer | Sell | 23,529 | 10.34 | 243,313 |
| Aug 21, 2026 | Stefan Constantin Ionel | Chief Technology Officer | Sell | 29,681 | 10.34 | 306,931 |
| Aug 21, 2026 | Sun Kang | Director | Sell | 62,101 | 10.34 | 642,186 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: October 30, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.