AMBQ
Ambiq Micro, Inc.
41.50$
-7.0%
vs. previous close
Closing price · As of: Nov 4, 2026
Ownership
Ownership Structure
Who owns Ambiq Micro, Inc. (AMBQ)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 89.1% of the shares are freely tradable; institutional investors hold 64.2%.
Institutional ownership
?Share of the stock held by institutional investors (funds, banks, insurers) according to regulatory filings.
64.2%
Insiders
?Share of the stock held by the executives, founders and major shareholders of the company itself.
5.7%
Float
?Share of stock freely tradable on the market — not locked up in the hands of founders, insiders, or major shareholders.
89.1%
Short % of float
?Shares sold short as a percentage of the freely tradable float — high values signal many bets on falling prices.
11.6%
Shares Outstanding
?Total number of shares issued. Price times share count gives market cap.
24Mio.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| BlackRock Inc | 5.71 | 1,380,623 | +36.3 | 06/30/2026 |
| T. Rowe Price Investment Management,Inc. | 4.16 | 1,006,359 | -20.6 | 06/30/2026 |
| D. E. Shaw & Co LP | 4.07 | 983,916 | +0.0 | 06/30/2026 |
| Atreides Management, LP | 3.63 | 877,123 | +1.7 | 06/30/2026 |
| State Street Corp | 3.56 | 861,979 | +231.2 | 06/30/2026 |
| Vanguard Capital Management, LLC | 3.18 | 768,539 | +8.6 | 06/30/2026 |
| Two Sigma Investments LLC | 2.70 | 651,786 | +1,671.4 | 06/30/2026 |
| AllianceBernstein L.P. | 2.52 | 609,607 | -11.1 | 06/30/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 2.66 | 643,350 | +0.0 | 09/30/2026 |
| iShares Russell 2000 ETF | 2.18 | 527,864 | -0.4 | 10/29/2026 |
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 |
|---|---|---|---|---|---|
| Esaka Fumihide | Chief Executive Officer | 443,900 | 18,421,850 $ | Oct 15, 2026 | direct |
| Hanson Scott McLean | Chief Technology Officer | 212,546 | 8,820,659 $ | Oct 15, 2026 | direct |
| Chen Sean Chihhsiang | President and COO | 106,268 | 4,410,122 $ | Oct 14, 2026 | direct |
| Winzeler Jeffrey G | Chief Financial Officer | 100,844 | 4,185,026 $ | Oct 2, 2026 | direct |
| Zhang Ker | Director | 20,366 | 845,189 $ | Sep 11, 2026 | direct |
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 |
|---|---|---|---|---|---|---|
| Oct 15, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 1,200 | 51.85 | 62,226 |
| Oct 15, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 2,800 | 51.15 | 143,214 |
| Oct 15, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 500 | 50.02 | 25,011 |
| Oct 15, 2026 | Esaka Fumihide | Chief Executive Officer | Other | 5,000 | 8.12 | 40,600 |
| Oct 15, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 1,800 | 51.86 | 93,351 |
| Oct 15, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 3,700 | 51.12 | 189,148 |
| Oct 15, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 900 | 50.08 | 45,074 |
| Oct 15, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 600 | 49.06 | 29,436 |
| Oct 15, 2026 | Hanson Scott McLean | Chief Technology Officer | Other | 7,000 | 8.12 | 56,840 |
| Oct 14, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 200 | 54.27 | 10,854 |
| Oct 14, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 4,000 | 53.44 | 213,745 |
| Oct 14, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 2,000 | 52.47 | 104,936 |
| Oct 14, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 1,261 | 51.53 | 64,980 |
| Oct 14, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 7,539 | 50.13 | 377,923 |
| Oct 14, 2026 | Chen Sean Chihhsiang | President and COO | Other | 15,000 | 8.12 | 121,800 |
| Oct 5, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 100 | 69.51 | 6,951 |
| Oct 5, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 800 | 68.08 | 54,461 |
| Oct 5, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 1,797 | 67.29 | 120,913 |
| Oct 5, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 5,508 | 66.38 | 365,625 |
| Oct 2, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 302 | 71.86 | 21,701 |
| Oct 2, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 3,008 | 69.77 | 209,875 |
| Oct 2, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 2,492 | 69.11 | 172,218 |
| Oct 2, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 862 | 71.86 | 61,943 |
| Oct 2, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 8,585 | 69.77 | 598,994 |
| Oct 2, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 7,113 | 69.11 | 491,567 |
| Oct 2, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 452 | 71.86 | 32,480 |
| Oct 2, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 4,500 | 69.77 | 313,975 |
| Oct 2, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 3,728 | 69.11 | 257,636 |
| Oct 2, 2026 | Winzeler Jeffrey G | Chief Financial Officer | Sell | 284 | 71.86 | 20,408 |
| Oct 2, 2026 | Winzeler Jeffrey G | Chief Financial Officer | Sell | 2,828 | 69.77 | 197,316 |
| Oct 2, 2026 | Winzeler Jeffrey G | Chief Financial Officer | Sell | 2,343 | 69.11 | 161,921 |
| Sep 15, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 100 | 61.00 | 6,100 |
| Sep 15, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 4,947 | 60.56 | 299,573 |
| Sep 15, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 1,953 | 59.53 | 116,270 |
| Sep 15, 2026 | Hanson Scott McLean | Chief Technology Officer | Other | 7,000 | 8.12 | 56,840 |
| Sep 15, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 100 | 61.00 | 6,100 |
| Sep 15, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 9,615 | 60.55 | 582,171 |
| Sep 15, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 3,785 | 59.56 | 225,444 |
| Sep 15, 2026 | Esaka Fumihide | Chief Executive Officer | Other | 13,500 | 8.12 | 109,620 |
| Sep 14, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 1,400 | 60.83 | 85,166 |
| Sep 14, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 11,000 | 60.24 | 662,618 |
| Sep 14, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 2,600 | 59.36 | 154,346 |
| Sep 14, 2026 | Chen Sean Chihhsiang | President and COO | Other | 15,000 | 8.12 | 121,800 |
| Sep 11, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 7,917 | 63.86 | 505,566 |
| Sep 11, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 42,083 | 63.27 | 2,662,427 |
| Sep 11, 2026 | Esaka Fumihide | Chief Executive Officer | Other | 50,000 | 12.60 | 630,000 |
| Sep 11, 2026 | Zhang Ker | Director | Sell | 900 | 63.95 | 57,552 |
| Sep 11, 2026 | Zhang Ker | Director | Sell | 9,100 | 63.39 | 576,809 |
| Sep 4, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 2,126 | 57.68 | 122,625 |
| Sep 4, 2026 | Chen Sean Chihhsiang | President and COO | Sell | 12,874 | 57.09 | 734,933 |
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: November 4, 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.