(AMSC)

Reporting relationship: SVP, CFO & Treasurer
Issuer ticker: AMSC
Reported as of: 11 Jun 2026
Net transaction value: -$253,579
SEC form: 4
Accepted by SEC: 11 Jun 2026, 16:31:39 UTC
Prior SEC filing: 10 Jun 2026
Source filing: View source filing
Reporting owner signature: /s/ John W. Kosiba, Jr.

Filing notes and source

Key filing fact

John W. Kosiba Jr. filed Form 4 for AMERICAN SUPERCONDUCTOR CORP /DE/ (AMSC) on 11 Jun 2026.

Key facts

This page summarizes John W. Kosiba Jr.'s Form 4 filing for AMERICAN SUPERCONDUCTOR CORP /DE/ (AMSC).
2 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 11 Jun 2026, 16:31.

Change

Previous filing in this sequence was filed on 10 Jun 2026.
Current net transaction value: -$253,579.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001703463 Primary reporting owner

Kosiba John W JR

Relationship: SVP, CFO & Treasurer
Address: C/O AMERICAN SUPERCONDUCTOR CORPORATION, 114 EAST MAIN ST, AYER
Signature: /s/ John W. Kosiba, Jr.
Signature date: 11 Jun 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

AMSC transaction

Common Stock

Sale

Transaction value: $187,604
Shares: -5,026
Change %: -1.5%
Price: $37.33
Shares after: 336,120
Date: 11 Jun 2026
Ownership: Direct
Footnotes: F1, F2

AMSC transaction

Common Stock

Sale

Transaction value: $65,975
Shares: -1,743
Change %: -0.52%
Price: $37.85
Shares after: 334,377
Date: 11 Jun 2026
Ownership: Direct
Footnotes: F1, F3, F4

AMSC holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 371
Date: 11 Jun 2026
Ownership: By 401(k) plan
Footnotes: F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 5 footnotes

Footnote 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.

Footnote F2

The sales were executed in multiple trades at prices ranging from $36.775-$37.73. 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.

Footnote F3

The sales were executed in multiple trades at prices ranging from $37.82-$38.06. 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.

Footnote F4

Following all the transactions reported on this Form 4, the reporting person holds 334,377 shares directly.

Footnote 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 11, 2026.