Eos Energy Enterprises, Inc.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

For the quarterly period ended September 30, 2026

OR

For the transition period from to

Commission file number 001-39291

EOS ENERGY ENTERPRISES, INC.

(Exact name of registrant as specified in its charter)

(732)225-8400

Registrant’s telephone number, including area code

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

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports); and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No☐

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes ☒ No☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

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. ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No☒

The registrant had outstanding 366,363,999 shares of common stock as of November 3, 2026.

FORWARD-LOOKING INFORMATION

All statements included in this Quarterly Report on Form 10-Q (“Quarterly Report”), other than statements or characterizations of historical fact, are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intends,” “may,” “might,” “plan,” “possible,” “potential,” “predict,” “project,” “should,” “would” and similar expressions, as they relate to us, are intended to identify forward-looking statements. These statements appear in a number of places in this Quarterly Report and include statements regarding the intent, belief or current expectations of Eos Energy Enterprises, Inc. Forward-looking statements are based on our management’s beliefs, as well as assumptions made by and information currently available to, them. Because such statements are based on expectations as to future financial and operating results and are not statements of fact, actual results may differ materially from those projected. Factors which may cause actual results to differ materially from current expectations include, but are not limited to:

•changes adversely affecting the business in which we are engaged;

•our ability to forecast trends accurately;

•our ability to generate cash, service indebtedness and incur additional indebtedness;

•our ability to raise financing in the future;

•our customers’ ability to secure project financing;

•risks associated with the Department of Energy Loan Facility and the Credit Agreement (each as defined below), including risks of default, dilution ofoutstanding common stock, consequences for failure to meet milestones and contractual lockup of shares;

•the amount of final tax credits available to our customers or to Eos pursuant to the Inflation Reduction Act including potential impacts from any repeal or modification of the legislation;

•the timing and availability of future funding under the Department of Energy Loan Facility;

•our ability to continue to develop efficient manufactu ring processes to scale and to forecast related costs and efficiencies accurately;

•fluctuations in our revenue and operating results;

•competition from existing or new competitors;

•our ability to convert firm order backlog and pipeline to revenue;

•risks associated with security breaches in our information technology systems;

•risks related to legal proceedings or claims;

•risks associated with evolving energy policies in the United States and other countries and the potential costs of regulatory compliance;

•risks associated with changes to the U.S. trade environment;

•our ability to maintain the listing of our shares of common stock on NASDAQ;

•our ability to grow our business and manage growth profitably, maintain relationships with customers and suppliers and retain our management and key employees;

•risks related to adverse changes in general economic conditions, including inflationary pressures and increased interest rates;

•risk from supply chain disruptions and other impacts of geopolitical conflict;

•changes in applicable laws or regulations; and

•other factors detailed under the section titled “Risk Factors” herein.

Should one or more of these risks or uncertainties materialize, or should any of our assumptions prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements. Forward-looking statements speak only as of the date they are made. Readers are cautioned not to put undue reliance on forward-looking statements and, except as required by law, the Company (as defined below) assumes no obligation and does not intend to update or revise these forward-looking statements, whether as a result of new information, future events, or otherwise. See also Part I, Item 1A,“Risk Factors” disclosures contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025 for additional discussion of the risks and uncertainties that could cause the Company’s actual results to differ materially from those expressed or implied in its forward-looking statements.