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Ambiq CEO sells 108K shares after option exercise

Ambiq Micro’s CEO exercised options for 117,771 shares and sold 108,500 shares in late August and early September 2026 under a Rule 10b5-1 plan.

(Neutral)
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Ambiq Micro, Inc. (AMBQ) reports that Chief Executive Officer and director Fumihide Esaka exercised stock options covering 117,771 shares of common stock at exercise prices of $8.12 and $12.60 per share between August 31 and September 2, 2026. Over the same period, he sold 108,500 shares of common stock in a series of open-market transactions at weighted-average prices reported between $55.45 and $58.74 per share. The filing states these transactions occurred under a Rule 10b5-1 trading plan adopted on May 15, 2026.

Positive

  • None.

Negative

  • None.
Insider Esaka Fumihide
Role Chief Executive Officer
Sold 108,500 shs ($6.17M)
Approx. gross sale proceeds $6.17M
Approx. exercise cost $1.42M
Type Security Shares Price Value
Exercise Stock Option (Right to Buy) F12 11,027 $0.00 $0.00
Exercise Common Stock 11,027 $12.60 $139K
Sale Common Stock F9 1,452 $56.1529 $82K
Sale Common Stock F10 9,575 $56.7701 $544K
Exercise Stock Option (Right to Buy) F12 48,973 $0.00 $0.00
Exercise Common Stock 48,973 $12.60 $617K
Sale Common Stock F8 48,973 $56.3889 $2.76M
Exercise Stock Option (Right to Buy) F1, F11 13,500 $0.00 $0.00
Exercise Stock Option (Right to Buy) F12 35,000 $0.00 $0.00
Exercise Stock Option (Right to Buy) F13 9,271 $0.00 $0.00
Exercise Common Stock F1 13,500 $8.12 $110K
Sale Common Stock F1, F2 5,899 $56.866 $335K
Sale Common Stock F1, F3 5,501 $57.7547 $318K
Sale Common Stock F1, F4 2,100 $58.5186 $123K
Exercise Common Stock 44,271 $12.60 $558K
Sale Common Stock F5 15,600 $56.8089 $886K
Sale Common Stock F6 13,800 $57.7012 $796K
Sale Common Stock F7 5,600 $58.4569 $327K
Holdings After Transaction: Stock Option (Right to Buy) — 266,286 contracts (Direct); Common Stock — 460,460 shares (Direct)
Footnotes (13)
  1. F1. The transactions occurred under a Rule 10b5-1 plan adopted by the Reporting Person on May 15, 2026.
  2. F2. The 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.
  3. F3. The 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.
  4. F4. The 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.
  5. F5. The 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.
  6. F6. The 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.
  7. F7. The 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.
  8. F8. The 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.
  9. F9. The 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.
  10. F10. The 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.
  11. F11. 1/4 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.
  12. F12. 1/48 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.
  13. F13. 1/4 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.
Shares sold 108,500 shares Total common shares sold by the CEO across reported transactions
Shares from option exercises 117,771 shares Common shares underlying options exercised by the CEO
Option exercise price (lower grant) $8.12 per share Exercise price for one set of stock options exercised on August 31, 2026
Option exercise price (higher grants) $12.60 per share Exercise price for multiple option grants exercised on August 31, September 1, and September 2, 2026
Lowest disclosed sale range $55.45 per share Low end of the disclosed price range for one weighted-average sale on September 2, 2026
Highest disclosed sale range $58.74 per share High end of the disclosed price range for one weighted-average sale on August 31, 2026
Rule 10b5-1 plan adoption date May 15, 2026 Date the CEO adopted the trading plan covering these transactions
Rule 10b5-1 plan regulatory
"The transactions occurred under a Rule 10b5-1 plan adopted by the Reporting Person on May 15, 2026"
A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.
weighted average sale price financial
"The reported price in Column 4 is a weighted average sale price"
vested financial
"1/4 of the shares subject to the option vested on February 21, 2020"
equal monthly installments financial
"1/48 of the shares subject to the option vested in equal monthly installments thereafter"

FAQ

What insider trading activity did AMBQ report for its CEO in this Form 4?

Ambiq Micro reported that CEO Fumihide Esaka exercised stock options for 117,771 shares of common stock and sold 108,500 shares in a series of open-market transactions between August 31 and September 2, 2026.

At what prices did the AMBQ CEO sell common shares?

The CEO’s sales used weighted-average prices reported between $55.45 and $58.74 per share, based on multiple transaction ranges disclosed for August 31 through September 2, 2026.

What were the option exercise prices in the AMBQ CEO’s Form 4?

The option exercises reported by Ambiq Micro’s CEO covered common shares at exercise prices of $8.12 and $12.60 per share, with expiration dates including February 20, 2029 and May 25, 2031.

Were the AMBQ CEO transactions made under a Rule 10b5-1 plan?

Yes. The filing states the transactions occurred under a Rule 10b5-1 plan adopted by the reporting person on May 15, 2026, indicating they were executed pursuant to a pre-arranged trading plan.

How many AMBQ shares did the CEO sell according to this Form 4?

According to the transaction summary, the CEO’s reported open-market sales totaled 108,500 shares of Ambiq Micro common stock across nine sale transactions.

How many AMBQ shares were obtained through option exercises in this filing?

The filing’s summary shows option exercises covering 117,771 shares of Ambiq Micro common stock across five exercise transactions during the reported period.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
X
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Esaka Fumihide

(Last)(First)(Middle)
C/O AMBIQ MICRO, INC.
6500 RIVER PLACE BLVD BUILDING 7 STE 200

(Street)
AUSTIN TEXAS 78730

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
Ambiq Micro, Inc. [ AMBQ ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
XOfficer (give title below)Other (specify below)
Chief Executive Officer
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
08/31/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock08/31/2026M(1)13,500A$8.12464,689D
Common Stock08/31/2026S(1)5,899D$56.866(2)458,790D
Common Stock08/31/2026S(1)5,501D$57.7547(3)453,289D
Common Stock08/31/2026S(1)2,100D$58.5186(4)451,189D
Common Stock08/31/2026M44,271A$12.6495,460D
Common Stock08/31/2026S15,600D$56.8089(5)479,860D
Common Stock08/31/2026S13,800D$57.7012(6)466,060D
Common Stock08/31/2026S5,600D$58.4569(7)460,460D
Common Stock09/01/2026M48,973A$12.6509,433D
Common Stock09/01/2026S48,973D$56.3889(8)460,460D
Common Stock09/02/2026M11,027A$12.6471,487D
Common Stock09/02/2026S1,452D$56.1529(9)470,035D
Common Stock09/02/2026S9,575D$56.7701(10)460,460D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Stock Option (Right to Buy)$8.1208/31/2026M(1)13,500 (11)02/20/2029Common Stock13,500$072,007D
Stock Option (Right to Buy)$12.608/31/2026M35,000 (12)05/25/2031Common Stock35,000$079,007D
Stock Option (Right to Buy)$12.608/31/2026M9,271 (13)07/20/2034Common Stock9,271$0175,272D
Stock Option (Right to Buy)$12.609/01/2026M48,973 (12)05/25/2031Common Stock48,973$030,034D
Stock Option (Right to Buy)$12.609/02/2026M11,027 (12)05/25/2031Common Stock11,027$019,007D
Explanation of Responses:
1. The transactions occurred under a Rule 10b5-1 plan adopted by the Reporting Person on May 15, 2026.
2. The 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.
3. The 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.
4. The 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.
5. The 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.
6. The 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.
7. The 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.
8. The 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.
9. The 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.
10. The 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.
11. 1/4 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.
12. 1/48 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.
13. 1/4 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.
/s/ Paula Floyd, Attorney-in-Fact09/02/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)