Ambiq Micro officer proposes $401K share sale

The planned sale is described as a sell-to-cover transaction for taxes owed on recently vested and settled restricted stock units.

Rhea-AI Filing Summary

Ambiq Micro, Inc. (AMBQ) officer Sean Chihhsiang Chen reported a proposed sale of 5,802 common shares, with an aggregate market value of $401,208.30 and an approximate sale date of October 2, 2026. Chen described it as a sell-to-cover transaction for taxes owed on recently vested and settled restricted stock units. The notice also lists sales of 15,000 shares on September 14, 2026, for $902,129.88 and 15,000 shares on September 4, 2026, for $857,557.50.

Key Figures

Proposed common shares for sale: 5,802 shares Aggregate market value: $401,208.30 Common shares sold: 15,000 shares +3 more

6 metrics

Proposed common shares for sale 5,802 shares Approximate sale date: October 2, 2026

Aggregate market value $401,208.30 Proposed sale

Common shares sold 15,000 shares September 14, 2026

Gross proceeds $902,129.88 Sale on September 14, 2026

Common shares sold 15,000 shares September 4, 2026

Gross proceeds $857,557.50 Sale on September 4, 2026

Key Terms

sell-to-cover transaction, restricted stock units, Rule 144

3 terms

sell-to-cover transaction financial

"This is a sell-to-cover transaction for taxes owed"

A sell-to-cover transaction is when a person granted company stock (for example as part of compensation or option exercise) immediately sells enough of those shares to pay required taxes or exercise costs and keeps the rest. Think of it like cashing part of a bonus to cover the tax bill; it provides necessary cash without the holder needing outside funds. Investors watch these sales because they increase trading volume and slightly reduce insider holdings, but they often reflect routine tax or cost management rather than a judgment on the company’s prospects.

restricted stock units financial

"recent vesting and settlement of restricted stock units"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144"

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many AMBQ shares did officer Sean Chihhsiang Chen propose to sell?

Sean Chihhsiang Chen reported a proposed sale of 5,802 common shares, with an aggregate market value of $401,208.30 and an approximate sale date of October 2, 2026.

What recent AMBQ share sales did Sean Chihhsiang Chen report?

The past-three-months section lists sales of 15,000 common shares on September 14, 2026, for $902,129.88 and 15,000 common shares on September 4, 2026, for $857,557.50.

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

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Available on EDGAR 10/02/2026 - 04:05 PM Accepted by SEC EDGAR 10/02/2026 - 04:04 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0002078559
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	AMBIQ MICRO, INC.
SEC File Number	001-42766
Address of Issuer	6500 RIVER PLACE BLVD. BUILDING 7 SUITE 200 AUSTIN TEXAS 78730
Phone	(512) 879-2850
Name of Person for Whose Account the Securities are To Be Sold	Sean Chihhsiang Chen
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common Stock	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza, 8th Floor New York NY 10004	5802	401208.30	24516643	10/02/2026	NYSE

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common Stock	10/02/2025	Restricted Stock Units	Issuer			5802	10/02/2025	Services Rendered

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Sean Chihhsiang Chen 6500 River Place Blvd. Building 7 Austin TX 78730	Common Stock	09/14/2026	15000	902129.88
Sean Chihhsiang Chen 6500 River Place Blvd. Building 7 Austin TX 78730	Common Stock	09/04/2026	15000	857557.50

144: Remarks and Signature

Remarks	This is a sell-to-cover transaction for taxes owed related to recent vesting and settlement of restricted stock units granted by the Issuer.
Date of Notice	10/02/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Sean Chihhsiang Chen
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)