UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): May 21, 2021

American Superconductor Corporation

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (978) 842-3000

Not Applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company  ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

On May 21, 2021, American Superconductor Corporation (the “Company”) filed a prospectus supplement with the Securities and Exchange Commission (the “SEC”) relating to shares of the Company’s common stock to be sold from time to time by certain selling stockholders of the Company. The prospectus supplement forms a part of the Company’s Registration Statement on Form S-3 (Reg. No. 333-253611), which was filed with the SEC and became effective on February 26, 2021.

Latham & Watkins LLP, counsel to the Company, has issued an opinion to the Company, dated May 21, 2021, regarding the validity of such shares. A copy of the opinion is filed as Exhibit 5.1 to this Current Report on Form 8-K.

(d) Exhibits:

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Exhibit 5.1

Stock, par value $0.01 per share

Ladies and Gentlemen:

We have acted as special counsel to American Superconductor Corporation, a Delaware corporation (the “Company”), in connection with the resale from time to time by the selling stockholders (the “Selling Stockholders”) named in the Registration Statement (as defined below) of 301,556 shares of common stock, $0.01 par value per share (the “Shares”). The Shares are included in a registration statement on Form S–3 under the Securities Act of 1933, as amended (the “Act”), filed with the Securities and Exchange Commission (the “Commission”) on February 26, 2021 (the “Registration Statement”). This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or the related Prospectus, other than as expressly stated herein with respect to the issue of the Shares.

As such counsel, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter. With your consent, we have relied upon certificates and other assurances of officers of the Company and others as to factual matters without having independently verified such factual matters. We are opining herein as to the General Corporation Law of the State of Delaware, and we express no opinion with respect to any other laws.

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, the issue of the Shares has been duly authorized by all necessary corporate action of the Company, and the Shares are validly issued, fully paid and nonassessable.

In rendering the foregoing opinion, we have assumed that the Company will comply with all applicable notice requirements regarding uncertificated shares provided in the General Corporation Law of the State of Delaware.

May 21, 2021

Page 2

This opinion is for your benefit in connection with the Registration Statement and may be relied upon by you and by persons entitled to rely upon it pursuant to the applicable provisions of the Act. We consent to your filing this opinion as an exhibit to the Company’s Form 8-K dated May 21, 2021 and to the reference to our firm in the Prospectus under the heading “Validity of the Common Stock.” In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission thereunder.