SEC Form 4 · accession 0002078454-26-000012
Ambiq Micro, Inc. · AMBQ
Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗
Reporting owner
Fumihide Esaka
Officer — Chief Executive Officer · Director
Period of report
Aug 31, 2026
Accepted (ET)
Sep 2, 2026 · 4:47 pm EDT
Rule 10b5-1 plan
yes — trade under a plan
Issuer CIK
0001500412
Table I — non-derivative securities
| Security | Date | Code | Shares | Price | A/D | Owned after | D/I | Nature of ownership |
|---|---|---|---|---|---|---|---|---|
| Common Stock | Aug 31, 2026 | M | 13,500 | $8.12 | A | 464,689 | D | |
| Common StockF2 | Aug 31, 2026 | S | 5,899 | $56.866 | D | 458,790 | D | |
| Common StockF3 | Aug 31, 2026 | S | 5,501 | $57.7547 | D | 453,289 | D | |
| Common StockF4 | Aug 31, 2026 | S | 2,100 | $58.5186 | D | 451,189 | D | |
| Common Stock | Aug 31, 2026 | M | 44,271 | $12.60 | A | 495,460 | D | |
| Common StockF5 | Aug 31, 2026 | S | 15,600 | $56.8089 | D | 479,860 | D | |
| Common StockF6 | Aug 31, 2026 | S | 13,800 | $57.7012 | D | 466,060 | D | |
| Common StockF7 | Aug 31, 2026 | S | 5,600 | $58.4569 | D | 460,460 | D | |
| Common Stock | Sep 1, 2026 | M | 48,973 | $12.60 | A | 509,433 | D | |
| Common StockF8 | Sep 1, 2026 | S | 48,973 | $56.3889 | D | 460,460 | D | |
| Common Stock | Sep 2, 2026 | M | 11,027 | $12.60 | A | 471,487 | D | |
| Common StockF9 | Sep 2, 2026 | S | 1,452 | $56.1529 | D | 470,035 | D | |
| Common StockF10 | Sep 2, 2026 | S | 9,575 | $56.7701 | D | 460,460 | D |
Table II — derivative securities
| Security | Conv. / exercise price | Date | Code | Shares | A/D | Exercisable | Expires | Underlying | Underlying shares | Owned after | D/I |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Stock Option (Right to Buy)F11 | $8.12 | Aug 31, 2026 | M | 13,500 | D | — | Feb 20, 2029 | Common Stock | 13,500 | 72,007 | D |
| Stock Option (Right to Buy)F12 | $12.60 | Aug 31, 2026 | M | 35,000 | D | — | May 25, 2031 | Common Stock | 35,000 | 79,007 | D |
| Stock Option (Right to Buy)F13 | $12.60 | Aug 31, 2026 | M | 9,271 | D | — | Jul 20, 2034 | Common Stock | 9,271 | 175,272 | D |
| Stock Option (Right to Buy)F12 | $12.60 | Sep 1, 2026 | M | 48,973 | D | — | May 25, 2031 | Common Stock | 48,973 | 30,034 | D |
| Stock Option (Right to Buy)F12 | $12.60 | Sep 2, 2026 | M | 11,027 | D | — | May 25, 2031 | Common Stock | 11,027 | 19,007 | D |
Explanation of responses
- F1The transactions occurred under a Rule 10b5-1 plan adopted by the Reporting Person on May 15, 2026.
- F10The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $56.46 to $57.06 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F111/4 of the shares subject to the option vested on February 21, 2020, and 1/48 of the shares subject to the option vested in equal monthly installments thereafter, subject to the Reporting Person's continued service.
- F121/48 of the shares subject to the option vested on June 26, 2021, and 1/48 of the shares subject to the option vested in equal monthly installments thereafter, subject to the Reporting Person's continued service.
- F131/4 of the shares subject to the option vested on January 1, 2024, and 1/48 of the shares subject to the option vest in equal monthly installments thereafter, subject to the Reporting Person's continued service.
- F2The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $56.35 to $57.34 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F3The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $57.37 to $58.24 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F4The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $58.42 to $58.74 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F5The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $56.29 to $57.28 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F6The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $57.29 to $58.28 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F7The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $58.29 to $58.49 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F8The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $56.00 to $56.83 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F9The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $55.45 to $56.44 per share. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.