[Form 4] Ambiq Micro, Inc. Insider Trading Activity

Ambiq Micro President and COO Sean Chihhsiang Chen reported an exercise-and-sell transaction in company stock.

Rhea-AI Filing Summary

Ambiq Micro President and COO Sean Chihhsiang Chen reported an exercise-and-sell transaction in company stock. On May 15, 2026, he exercised stock options for 55,685 shares of Common Stock at $5.88 per share and sold an equal number of shares in open-market trades.

The sales were split into 23,334 shares at a weighted average price of $71.3746 and 32,351 shares at a weighted average price of $70.5334, executed across multiple transactions within disclosed price ranges. After these transactions, Chen directly held 120,275 shares of Ambiq Micro common stock, indicating he retains a substantial equity position following the option exercise and related sales.

Insider Trade Summary

Exercise and Sale: 55,685 shares ($3.62M approx. pre-tax spread)

Exercise and Sale 4 txns

Insider Chen Sean Chihhsiang

Role President and COO

Sold 55,685 shs ($3.95M)

Approx. gross sale proceeds $3.95M

Approx. exercise cost $327K

Approx. pre-tax spread $3.62M

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy)	55,685	$0.00	$0.00
Exercise	Common Stock	55,685	$5.88	$327K
Sale	Common Stock	32,351	$70.5334	$2.28M
Sale	Common Stock	23,334	$71.3746	$1.67M

Holdings After Transaction: Stock Option (Right to Buy) — 1 contracts (Direct); Common Stock — 120,275 shares (Direct)

Footnotes (3)

1. F1. The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $70.02 to $71.0097 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.
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 $71.025 to $71.85 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. 1/4 of the shares subject to the option vested on November 3, 2017, and 1/48 of the shares subject to the option vested in equal monthly installments thereafter, subject to the Reporting Person's continued service.

FAQ

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What insider transaction did Ambiq Micro (AMBQ) report for Sean Chen?

Ambiq Micro reported that President and COO Sean Chihhsiang Chen exercised options for 55,685 common shares and sold 55,685 shares in open-market transactions on May 15, 2026, as disclosed in his Form 4 insider trading report.

How many Ambiq Micro (AMBQ) shares did Sean Chen sell and at what prices?

Sean Chen sold 55,685 Ambiq Micro common shares in two weighted-average tranches: 23,334 shares at $71.3746 and 32,351 shares at $70.5334, with individual trades executed within specified price ranges described in the Form 4 footnotes.

What stock options did Ambiq Micro (AMBQ) executive Sean Chen exercise?

Sean Chen exercised stock options covering 55,685 Ambiq Micro common shares at an exercise price of $5.88 per share. The option originally vested quarterly and monthly beginning November 3, 2017, as outlined in the vesting schedule footnote in the Form 4 filing.

How many Ambiq Micro (AMBQ) shares does Sean Chen own after this Form 4?

Following the reported May 15, 2026 transactions, Sean Chen directly owns 175,960 shares of Ambiq Micro common stock. This figure reflects his position after exercising 55,685 options and selling 55,685 shares in open-market transactions disclosed in the Form 4.

Were Sean Chen’s Ambiq Micro (AMBQ) share sales open-market transactions?

Yes. The Form 4 states both sales were coded “S” as open-market or private transactions, with reported weighted average prices and detailed intraday price ranges available upon request, indicating routine market sales rather than privately negotiated option exercises alone.

What does the Form 4 say about the pricing of Sean Chen’s Ambiq Micro (AMBQ) sales?

The Form 4 notes that each reported sale price is a weighted average. One block sold between $70.02 and $71.0097 per share, and the other between $71.025 and $71.85 per share, with full breakdowns available from the company or the reporting person on request.

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Form 4 Insider Transactions: What Each Field Means →

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Accepted by SEC EDGAR 05/18/2026 - 05:48 PM Learn about SEC filing dates

SEC Form 4

FORM 4

UNITED 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).

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^*

Chen Sean Chihhsiang

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and COO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/15/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form 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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	05/15/2026		M		55,685	A	$5.88	175,960	D
Common Stock	05/15/2026		S		32,351	D	$70.5334(1)	143,609	D
Common Stock	05/15/2026		S		23,334	D	$71.3746(2)	120,275	D

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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$5.88	05/15/2026		M			55,685	(3)	11/02/2026	Common Stock	55,685	$0	1	D

Explanation of Responses:

1. The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $70.02 to $71.0097 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.

2. The reported price in Column 4 is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $71.025 to $71.85 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. 1/4 of the shares subject to the option vested on November 3, 2017, and 1/48 of the shares subject to the option vested in equal monthly installments thereafter, subject to the Reporting Person's continued service.

	/s/ Jeffrey Winzeler, Attorney-in-Fact	05/18/2026
	** Signature of Reporting Person	Date
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)