Vanguard reports 4.93% stake in American Superconductor

Vanguard Capital Management filed an amended Schedule 13G reporting beneficial ownership of American Superconductor Corp common stock.

Rhea-AI Filing Summary

Vanguard Capital Management filed an amended Schedule 13G reporting beneficial ownership of American Superconductor Corp common stock. Vanguard reports beneficial ownership of 2,390,425 shares, representing 4.93% of the outstanding common stock as of June 30, 2026. It has sole voting power over 356,206 shares and sole dispositive power over all 2,390,425 shares, with no shared voting or dispositive power. The filing aggregates holdings across specified Vanguard affiliates and investment funds where Vanguard exercises dispositive and/or voting power.

Key Figures

Beneficially owned shares: 2,390,425 shares Percent of class owned: 4.93% Sole voting power: 356,206 shares +4 more

7 metrics

Beneficially owned shares 2,390,425 shares Shares of American Superconductor Corp common stock beneficially owned by Vanguard Capital Management

Percent of class owned 4.93% Portion of American Superconductor Corp common stock class beneficially owned

Sole voting power 356,206 shares Shares over which Vanguard Capital Management has sole power to vote or direct the vote

Shared voting power 0 Shares over which Vanguard Capital Management has shared power to vote

Sole dispositive power 2,390,425 shares Shares over which Vanguard Capital Management has sole power to dispose or direct disposition

Shared dispositive power 0 Shares over which Vanguard Capital Management has shared dispositive power

As-of date 06/30/2026 Date as of which the ownership information is reported

Key Terms

beneficially owned, sole dispositive power, sole voting power, Schedule 13G, +1 more

5 terms

beneficially owned financial

"this reflects the securities beneficially owned, or deemed to be beneficially owned, by Vanguard"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

sole dispositive power financial

"Sole Dispositive Power 2,390,425.00"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

sole voting power financial

"Sole Voting Power 356,206.00"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

Schedule 13G regulatory

"In accordance with SEC Release No. 34-39538 (January 12, 1998), this reflects the securities"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

percent of class financial

"Percent of class: 4.93 %"

Percent of class is the portion of a specific category of securities—such as a company’s common shares, preferred shares, or a bond series—that takes part in or approves a corporate action (vote, consent, tender, etc.). Investors watch this number because it reveals how much support or opposition exists within that particular shareholder group; like counting how many members of a club back a proposal, it can determine whether a plan passes or how influence is distributed.

FAQ

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

What percentage of American Superconductor Corp (AMSC) does Vanguard Capital Management report owning?

Vanguard Capital Management reports beneficial ownership of 4.93% of American Superconductor Corp’s common stock, representing 2,390,425 shares as of June 30, 2026, across certain Vanguard affiliates and managed funds.

How many AMSC shares does Vanguard Capital Management have voting power over?

Vanguard Capital Management has sole voting power over 356,206 shares of American Superconductor Corp common stock and no shared voting power, according to the Schedule 13G/A filing.

How many AMSC shares can Vanguard Capital Management dispose of under its sole authority?

Vanguard Capital Management has sole dispositive power over 2,390,425 shares of American Superconductor Corp common stock and no shared dispositive power, meaning it can decide how to dispose of those shares.

Which entities are included in Vanguard Capital Management’s reported AMSC holdings?

The reported beneficial ownership includes securities over which Vanguard Capital Management LLC and affiliates such as Vanguard Asset Management Limited, Vanguard Fiduciary Trust Company, Vanguard Global Advisers, LLC, and Vanguard Investments Australia Ltd exercise dispositive or voting power.

Does any single client of Vanguard hold more than 5% of AMSC according to this filing?

No. The filing states that while Vanguard and its managed accounts may receive dividends or sale proceeds, no one other person's interest in the reported American Superconductor Corp securities is more than 5% of the class.

Why does the Schedule 13G/A for AMSC note ownership of 5 percent or less?

Item 5 indicates ownership of 5 percent or less of the class of American Superconductor Corp common stock, confirming that Vanguard Capital Management’s reported 4.93% beneficial ownership is below the 5% threshold.

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

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Available on EDGAR 07/31/2026 - 09:56 AM Accepted by SEC EDGAR 07/31/2026 - 09:56 AM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

American Superconductor Corp

(Name of Issuer)

Common Stock

(Title of Class of Securities)

030111207

(CUSIP Number)

06/30/2026

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 030111207

1

Names of Reporting Persons

Vanguard Capital Management

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

PENNSYLVANIA

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 356,206.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 2,390,425.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,390,425.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

4.93 %

12

Type of Reporting Person (See Instructions)

IA

Comment for Type of Reporting Person: In accordance with SEC Release No. 34-39538 (January 12, 1998), this Schedule 13G reflects the securities beneficially owned, or deemed to be beneficially owned, by Vanguard Capital Management LLC and the following affiliates of Vanguard Capital Management LLC or business divisions of such affiliates: Vanguard Asset Management Limited, Vanguard Fiduciary Trust Company, Vanguard Global Advisers, LLC and Vanguard Investments Australia Ltd. This Schedule 13G includes securities held by Vanguard funds, or sleeves thereof, over which Vanguard Capital Management LLC exercises dispositive power, in addition to securities held by clients over which the affiliates or business divisions of such affiliates indicated above exercise dispositive and/or voting power. This Schedule 13G does not include securities, if any, beneficially owned by other subsidiaries or affiliates of Vanguard Capital Management LLC, or business divisions of such subsidiaries, whose ownership of securities is disaggregated from that of the reporting business unit in accordance with such release.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: American Superconductor Corp
(b)	Address of issuer's principal executive offices: 114 East Main Street, Ayer, MA, 01432
Item 2.
(a)	Name of person filing: Vanguard Capital Management
(b)	Address or principal business office or, if none, residence: 100 Vanguard Blvd,, Malvern, PA, 19355
(c)	Citizenship: PA
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 030111207
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 2390425
(b)	Percent of class: 4.93 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 356206
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 2390425
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. Vanguard Capital Management, including investment companies registered under the Investment Company Act of 1940 and other managed accounts, have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the securities reported herein.No one other person's interest in the securities reported herein is more than 5%.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Vanguard Capital Management

Signature:	My Trieu-Gatt
Name/Title:	Authorized Signatory, Head of Global Fund Administration
Date:	07/31/2026