AMBQ
Ambiq Micro, Inc.
62.40$
+4.1%
vs. previous close
Closing price · As of: Sep 17, 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. 89.6% 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.
89.6%
Short % of float
?Shares sold short as a percentage of the freely tradable float — high values signal many bets on falling prices.
7.9%
Shares Outstanding
?Total number of shares issued. Price times share count gives market cap.
24Mio.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| T. Rowe Price Investment Management,Inc. | 5.24 | 1,267,551 | +0.0 | 03/31/2026 |
| BlackRock Inc | 4.19 | 1,013,161 | +229.1 | 03/31/2026 |
| 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 |
| Vanguard Capital Management, LLC | 2.93 | 707,404 | +0.0 | 03/31/2026 |
| AllianceBernstein L.P. | 2.84 | 686,098 | +73.5 | 03/31/2026 |
| Schonfeld Strategic Advisors LLC | 2.71 | 656,552 | +196.0 | 03/31/2026 |
| Two Sigma Investments LLC | 2.70 | 651,786 | +1,671.4 | 06/30/2026 |
| Franklin Templeton Inc | 2.24 | 542,216 | +76.1 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Vanguard MStar Total Stk Mkt Idx Invest | 2.66 | 643,350 | +0.0 | 07/31/2026 |
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 | 460,460 | 28,732,704 $ | Sep 15, 2026 | direct |
| Hanson Scott McLean | Chief Technology Officer | 221,226 | 13,804,502 $ | Aug 27, 2026 | direct |
| Chen Sean Chihhsiang | President and COO | 120,275 | 7,505,160 $ | Sep 14, 2026 | direct |
| Zhang Ker | Director | 20,366 | 1,270,838 $ | 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 |
|---|---|---|---|---|---|---|
| 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 |
| Sep 4, 2026 | Chen Sean Chihhsiang | President and COO | Other | 15,000 | 8.12 | 121,800 |
| Sep 4, 2026 | Zhang Ker | Director | Sell | 185 | 56.92 | 10,530 |
| Sep 4, 2026 | Zhang Ker | Director | Other | 1,785 | 5.88 | 10,496 |
| Sep 2, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 9,575 | 56.77 | 543,574 |
| Sep 2, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 1,452 | 56.15 | 81,534 |
| Sep 2, 2026 | Esaka Fumihide | Chief Executive Officer | Other | 11,027 | 12.60 | 138,940 |
| Sep 1, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 48,973 | 56.39 | 2,761,534 |
| Sep 1, 2026 | Esaka Fumihide | Chief Executive Officer | Other | 48,973 | 12.60 | 617,060 |
| Aug 31, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 5,600 | 58.46 | 327,359 |
| Aug 31, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 13,800 | 57.70 | 796,277 |
| Aug 31, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 15,600 | 56.81 | 886,219 |
| Aug 31, 2026 | Esaka Fumihide | Chief Executive Officer | Other | 44,271 | 12.60 | 557,815 |
| Aug 31, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 2,100 | 58.52 | 122,889 |
| Aug 31, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 5,501 | 57.75 | 317,709 |
| Aug 31, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 5,899 | 56.87 | 335,453 |
| Aug 31, 2026 | Esaka Fumihide | Chief Executive Officer | Other | 13,500 | 8.12 | 109,620 |
| Aug 27, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 4,910 | 60.32 | 296,176 |
| Aug 27, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 22,590 | 59.69 | 1,348,433 |
| Aug 27, 2026 | Hanson Scott McLean | Chief Technology Officer | Other | 27,500 | 8.12 | 223,300 |
| Aug 26, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 27,500 | 59.58 | 1,638,469 |
| Aug 26, 2026 | Hanson Scott McLean | Chief Technology Officer | Other | 27,500 | 8.12 | 223,300 |
| Aug 26, 2026 | Hanson Scott McLean | Chief Technology Officer | Other | 10,000 | 8.12 | 81,200 |
| Aug 14, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 1,500 | 65.26 | 97,893 |
| Aug 14, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 10,718 | 64.40 | 690,201 |
| Aug 14, 2026 | Esaka Fumihide | Chief Executive Officer | Sell | 1,282 | 63.29 | 81,132 |
| Aug 14, 2026 | Esaka Fumihide | Chief Executive Officer | Other | 13,500 | 8.12 | 109,620 |
| Aug 14, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 5,400 | 64.41 | 347,793 |
| Aug 14, 2026 | Hanson Scott McLean | Chief Technology Officer | Sell | 800 | 65.30 | 52,241 |
| Aug 14, 2026 | Hanson Scott McLean | Chief Technology Officer | Other | 7,000 | 8.12 | 56,840 |
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: September 17, 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.