Results of Operations and Financial Condition. ​ On September 2, 2026, FuelCell Energy, Inc. (the “Company”) issued a press release announcing its financial results and providing a business update as of and for the three and nine months ended July 31, 2026. A copy of this press release is furnished with this report as Exhibit 99.1 and is incorporated herein by reference. ​ The information furnished in this Item 2.02, including Exhibit 99.1, is not deemed to be “filed” for purposes of Section…

Other Events. On July 21, 2026, FuelCell Energy, Inc. (the “Company”) filed a prospectus supplement to its automatic shelf registration statement on Form S-3 (Registration No. 333-296607) with the Securities and Exchange Commission. This Current Report on Form 8-K is being filed solely for the purpose of filing the opinion of Latham & Watkins LLP relating to the legality of the issuance and sale of the securities set forth in the prospectus supplement, which opinion is attached as Exhibit 5.1…

Entry into a Material Definitive Agreement. On July 7, 2026, FuelCell Energy, Inc. (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Citigroup Global Markets Inc. and Barclays Capital Inc., as representatives of the several underwriters named in Schedule II thereto (the “Underwriters”), relating to the previously announced underwritten offering of 10,714,286 shares (the “Shares”) of the Company’s common stock, $0.0001 par value (the “Common Stock” and…

Unregistered Sales of Equity Securities. On June 22, 2026, the Company entered into the Warrant Agreement, pursuant to which it issued Warrants to purchase shares of Common Stock in a private placement in reliance on the exemption from the registration requirements of the Securities Act provided by Section 4(a)(2) of the Securities Act. The information contained in

Entry Into a Material Definitive Agreement. Warrant Agreement On June 22, 2026, in connection with the CEPA, the Company entered into a warrant agreement (the “Warrant Agreement”) with Fit, pursuant to which the Company issued to Fit three tranches of warrants representing Fit’s right to purchase up to an aggregate of 12,000,000 shares of the Company’s common stock, par value $0.0001 per share (the “Common Stock”) at an exercise price of $26.44 per share (the “Strike Price”). The warrants are…

Results of Operations and Financial Condition. ​ On June 8, 2026, FuelCell Energy, Inc. (the “Company”) issued a press release announcing its financial results and providing a business update as of and for the three and six months ended April 30, 2026. A copy of this press release is furnished with this report as Exhibit 99.1 and is incorporated herein by reference. ​ The information furnished in this Item 2.02, including Exhibit 99.1, is not deemed to be “filed” for purposes of Section 18 of…

Director — John Livingston: Election of a new director to the Board and appointment to committees.

The filing pertains to the approval of incentive and stock purchase plans, not a management change.

Results of Operations and Financial Condition. ​ On March 9, 2026, FuelCell Energy, Inc. (the “Company”) issued a press release announcing its financial results and providing a business update as of and for the three months ended January 31, 2026. A copy of this press release is furnished with this report as Exhibit 99.1 and is incorporated herein by reference. ​ The information furnished in this Item 2.02, including Exhibit 99.1, is not deemed to be “filed” for purposes of Section 18 of the…

Executive Vice President, General Counsel and Corporate Secretary — Joshua Dolger: The employment relationship between FuelCell Energy, Inc. and Joshua Dolger ended effective as of January 6, 2026.

Executive Vice President, General Counsel and Corporate Secretary — Joshua Dolger: The company ended its employment relationship with Joshua Dolger without cause.

Entry into a Material Definitive Agreement. On December 30, 2025, FuelCell Energy, Inc. (the “Company”) entered into an amendment to the Open Market Sale Agreement SM (as amended, the “Sales Agreement”) with Jefferies LLC, B. Riley Securities, Inc., Barclays Capital Inc., BMO Capital Markets Corp., BofA Securities, Inc., Canaccord Genuity LLC, Citigroup Global Markets Inc. and Loop Capital Markets LLC, as sales agents, to increase the amount of shares of common stock that may be sold under th…

Results of Operations and Financial Condition. ​ On December 18, 2025, FuelCell Energy, Inc. (the “Company”) issued a press release announcing its financial results and providing a business update as of and for the three months and year ended October 31, 2025. A copy of this press release is furnished with this report as Exhibit 99.1 and is incorporated herein by reference. ​ The information furnished in this Item 2.02, including Exhibit 99.1, is not deemed to be “filed” for purposes of Secti…

The filing describes the approval of long-term incentive plan awards for named executive officers and does not involve any change in management or departure.

Results of Operations and Financial Condition. ​ On September 9, 2025, FuelCell Energy, Inc. (the “Company”) issued a press release announcing its financial results and providing a business update as of and for the three and nine months ended July 31, 2025. A copy of this press release is furnished with this report as Exhibit 99.1 and is incorporated herein by reference. ​ The information furnished in this Item 2.02, including Exhibit 99.1, is not deemed to be “filed” for purposes of Section…

Executive Vice President, Strategic Partnerships — Michael Lisowski: The company ended its employment relationship with Michael Lisowski without cause.

Results of Operations and Financial Condition. ​ On June 6, 2025, FuelCell Energy, Inc. (the “Company”) issued a press release announcing its financial results and providing a business update as of and for the three and six months ended April 30, 2025. A copy of this press release is furnished with this report as Exhibit 99.1 and is incorporated herein by reference. ​ The information furnished in this Item 2.02, including Exhibit 99.1, is not deemed to be “filed” for purposes of Section 18 of…

Executive Vice President and Chief Commercial Officer — Mark Feasel: The company ended its employment relationship with Mark Feasel without cause.

The filing pertains to the approval of an amended and restated incentive plan, not a management change.

Results of Operations and Financial Condition. ​ On March 11, 2025, FuelCell Energy, Inc. (the “Company”) issued a press release announcing its financial results and providing a business update as of and for the three months ended January 31, 2025. A copy of this press release is furnished with this report as Exhibit 99.1 and is incorporated herein by reference. ​ The information furnished in this Item 2.02, including Exhibit 99.1, is not deemed to be “filed” for purposes of Section 18 of the…

The filing describes the approval of long-term incentive plan awards for named executive officers and does not involve any management changes.

Results of Operations and Financial Condition. ​ On December 19, 2024, FuelCell Energy, Inc. (the “Company”) issued a press release announcing its financial results and providing a business update as of and for the three months and year ended October 31, 2024. A copy of this press release is furnished with this report as Exhibit 99.1 and is incorporated herein by reference. ​ The information furnished in this Item 2.02, including Exhibit 99.1, is not deemed to be “filed” for purposes of Secti…

Results of Operations and Financial Condition. ​ On November 15, 2024, FuelCell Energy, Inc. (the “Company”) issued a press release announcing a restructuring plan and workforce reduction. The press release contains preliminary unaudited information about the Company’s estimated cash and cash equivalents, restricted cash and cash equivalents, and short-term investments as of its fiscal year end, October 31, 2024. A copy of this press release is furnished with this report as Exhibit 99.1 and i…

Costs Associated with Exit or Disposal Activities. ​ On November 13, 2024, the Company’s Board of Directors approved a global restructuring of its operations in the U.S., Canada and Germany. The restructuring plan is aimed at reducing operating costs and better aligning its workforce with the needs of the Company’s business and its customers. Pursuant to the restructuring plan, the Company reduced its workforce by approximately 13% or 75 employees. The actions under the restructuring plan are…

Material Modification to Rights of Security Holders. To the extent required by