AMSC CFO sells shares for tax withholding

American Superconductor senior vice president, CFO and treasurer John W. Kosiba Jr. reported open-market sales of common stock that were used to cover tax withholding on vesting restricted stock awards.

Rhea-AI Filing Summary

American Superconductor senior vice president, CFO and treasurer John W. Kosiba Jr. reported open-market sales of common stock that were used to cover tax withholding on vesting restricted stock awards. On June 8, 2026, he sold 3,286 shares at a weighted average price of $41.5007 and 1,549 shares at a weighted average price of $42.347, in multiple trades within disclosed price ranges. The transactions were executed under a pre-arranged Rule 10b5-1 trading plan. After these transactions, he holds 341,146 shares directly and 371 shares indirectly through the company’s 401(k) plan as of June 10, 2026.

Insider Trade Summary 10b5-1

Net Seller: 4,835 shares

Net Sell 3 txns

Insider Kosiba John W JR

Role SVP, CFO & Treasurer

Sold 4,835 shs ($202K)

Type	Security	Shares	Price	Value
Sale	Common Stock	3,286	$41.5007	$136K
Sale	Common Stock	1,549	$42.347	$66K
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 341,146 shares (Direct); Common Stock — 371 shares (Indirect, By 401(k) plan)

Footnotes (5)

1. F1. Represents the number of shares sold by the reporting person to cover tax withholding obligations in connection with the vesting of restricted stock awards. The reported transaction was effected pursuant to a Rule 10b5-1 trading plan previously entered into by the reporting person on August 15, 2025.
2. F2. The sales were executed in multiple trades at prices ranging from $40.94-$41.90. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares and prices at which the transactions were effected.
3. F3. The sales were executed in multiple trades at prices ranging from $41.94-$42.86. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares and prices at which the transactions were effected.
4. F4. Following all the transactions reported on this Form 4, the reporting person holds 341,146 shares directly.
5. F5. Following all the transactions reported on this Form 4, the reporting person holds 371 shares indirectly through the company's 401(k) plan as of June 10, 2026.

Key Figures

Shares sold total: 4,835 shares First sale size: 3,286 shares Second sale size: 1,549 shares +4 more

7 metrics

Shares sold total 4,835 shares Common stock sold on June 8, 2026

First sale size 3,286 shares Common stock open-market sale on June 8, 2026

Second sale size 1,549 shares Common stock open-market sale on June 8, 2026

First weighted average price $41.5007 per share Weighted average price for 3,286-share sale

Second weighted average price $42.347 per share Weighted average price for 1,549-share sale

Direct holdings after sale 341,146 shares Directly held following all reported transactions

Indirect 401(k) holdings 371 shares Held indirectly via company 401(k) plan as of June 10, 2026

Key Terms

Rule 10b5-1 trading plan, restricted stock awards, weighted average sale price, 401(k) plan

4 terms

Rule 10b5-1 trading plan regulatory

"The reported transaction was effected pursuant to a Rule 10b5-1 trading plan previously entered into by the reporting person"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

restricted stock awards financial

"tax withholding obligations in connection with the vesting of restricted stock awards"

Restricted stock awards are company shares given to employees or executives that cannot be sold or transferred until certain conditions — like staying with the company for a set time or meeting performance targets — are met, like a gift that is locked in a safe until rules are satisfied. Investors care because these awards tie management’s pay to company performance, can increase the number of shares outstanding when they become tradable (dilution), and may signal expected future selling pressure or commitment to long-term growth.

weighted average sale price financial

"The price reported above reflects the weighted average sale price"

401(k) plan financial

"holds 371 shares indirectly through the company's 401(k) plan as of June 10, 2026"

A 401(k) plan is a workplace retirement account that lets employees set aside part of their pay into a tax-advantaged savings pot, often with employers adding matching contributions — like a workplace piggy bank for future income. It matters to investors because the amount people save and how employers fund these plans influence consumer spending, corporate payroll costs and the flow of money into financial markets, which can affect stock prices and company valuations.

FAQ

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

What insider transaction did AMSC CFO John W. Kosiba Jr. report?

He reported selling common stock to cover tax withholding obligations from vesting restricted stock awards. The filing shows two open-market sales on June 8, 2026, executed under a pre-arranged Rule 10b5-1 trading plan.

How many AMSC shares did the CFO sell in this Form 4 filing?

He sold a total of 4,835 shares of American Superconductor common stock. The transactions comprised 3,286 shares in one sale and 1,549 shares in another, both dated June 8, 2026, according to the reported Form 4 data.

At what prices were the AMSC shares sold by the CFO?

The filing reports weighted average sale prices of $41.5007 and $42.347 per share. Footnotes note each sale occurred through multiple trades within price ranges from $40.94 to $42.86, with full trade details available upon request.

Why were AMSC shares sold by the CFO according to the Form 4?

The shares were sold to satisfy tax withholding obligations tied to the vesting of restricted stock awards. This type of transaction is typically mechanical, ensuring required taxes are paid when equity compensation vests, rather than a discretionary portfolio decision.

Was the AMSC CFO’s share sale done under a Rule 10b5-1 plan?

Yes. A footnote states the reported transaction was effected under a Rule 10b5-1 trading plan. That plan had been previously entered into by the reporting person, helping show the sales were pre-scheduled rather than timed in response to recent company developments.

How many AMSC shares does the CFO hold after these transactions?

After the reported sales, he holds 341,146 shares of American Superconductor common stock directly. A separate footnote adds that he also holds 371 shares indirectly through the company’s 401(k) plan as of June 10, 2026.

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

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Accepted by SEC EDGAR 06/10/2026 - 04:55 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).

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^*

Kosiba John W JR

(Last) (First) (Middle)

C/O AMERICAN SUPERCONDUCTOR CORPORATION

114 EAST MAIN ST

(Street)

AYER MASSACHUSETTS 01432

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
AMERICAN SUPERCONDUCTOR CORP /DE/ [ AMSC ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	SVP, CFO & Treasurer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/08/2026

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	06/08/2026		S(1)		3,286	D	$41.5007(2)	342,695	D
Common Stock	06/08/2026		S(1)		1,549	D	$42.347(3)	341,146(4)	D
Common Stock								371(5)	I	By 401(k) plan

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

Explanation of Responses:

1. Represents the number of shares sold by the reporting person to cover tax withholding obligations in connection with the vesting of restricted stock awards. The reported transaction was effected pursuant to a Rule 10b5-1 trading plan previously entered into by the reporting person on August 15, 2025.

2. The sales were executed in multiple trades at prices ranging from $40.94-$41.90. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares and prices at which the transactions were effected.

3. The sales were executed in multiple trades at prices ranging from $41.94-$42.86. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide, upon request, to the SEC staff, the issuer, or a security holder of the issuer, full information regarding the number of shares and prices at which the transactions were effected.

4. Following all the transactions reported on this Form 4, the reporting person holds 341,146 shares directly.

5. Following all the transactions reported on this Form 4, the reporting person holds 371 shares indirectly through the company's 401(k) plan as of June 10, 2026.

	/s/ John W. Kosiba, Jr.	06/10/2026
	** 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)