STEM, INC.

To the shareholders and the Board of Directors of Stem, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Stem, Inc. and subsidiaries (the "Company") as of December 31, 2025 and 2024, the related consolidated statements of operations, comprehensive income (loss), stockholders’ equity (deficit), and cash flows, for each of the three years in the period ended December 31, 2025, and the related notes (collectively referred to as the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control — Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated March 4, 2026, expressed an unqualified opinion on the Company's internal control over financial reporting.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company's financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current-period audit of the financial statements that were communicated or required to be communicated to the audit committee and that (1) relate to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing separate opinions on the critical audit matter or on the accounts or disclosures to which it relates.

Fair Value Measurements – 2030 Senior Secured Notes – Refer to Note 11 to the financial statements

Critical Audit Matter Description

On June 30, 2025, the Company issued $155.4 million of 2030 Senior Secured Notes to the holders of its 2028 Convertible Notes and 2030 Convertible Notes in a privately negotiated exchange pursuant to Rule 144A under the Securities Act of 1933, as amended. The transaction included an exchange of approximately (i) $228.8 million principal amount of the existing 2028 Convertible Notes and (ii) $121.3 million principal amount of the 2030 Convertible Notes less amounts in lieu of fractional notes, for the 2030 Senior Secured Notes, warrants to purchase 439,919 shares of common stock (the “2030 Private Placement Warrants”), (iii) $10.0 million of cash proceeds, and accrued and unpaid interest on the exchanged 2028 Convertible Notes and 2030 Convertible Notes. The exchange resulted in a $220.0 million gain on debt extinguishment which represents the proportional carrying value of the exchanged 2028 Convertible Notes and 2030 Convertible Notes, which in aggregate was $343.9 million, reduced by the collective fair value of the 2030 Senior Secured Notes of $132.0 million and the fair value of the 2030 Private Placement Warrants of $1.9 million, offset by cash received. The fair value of the 2030 Senior Secured Notes was estimated using the Black Derman-Toy lattice model. The Black Derman-Toy lattice inputs used to value the 2030 Senior Secured Notes includes synthetic credit rating of the Company, yield, and volatility.

We identified the fair value measurements of the 2030 Senior Secured Notes as a critical audit matter due to the significant level of management judgment required in selection of the valuation model and the inputs management used in the Black Derman-Toy lattice model, including selection of synthetic credit rating, yield, and volatility. This required a high degree of auditor judgment and an increased extent of effort, including the need to involve our fair value specialists who possess significant quantitative and modeling expertise, when performing audit procedures to evaluate the appropriateness of the model and management’s inputs.

How the Critical Audit Matter Was Addressed in the Audit

Our audit procedures related to testing the fair value of the 2030 Senior Secured Notes included the following, among others:

•We read the relevant debt agreements and other supporting documents to test the source information underlying the fair value measurements of the 2030 Senior Secured Notes and the mathematical accuracy of management’s calculations.

•We tested the effectiveness of controls over the estimation process supporting the fair value estimates of the 2030 Senior Secured Notes, including management’s controls over the selection of the valuation model, synthetic credit rating, yield, and volatility used.

•With the assistance of fair value specialists, we evaluated the reasonableness of the valuation model and the inputs including selection of synthetic credit rating, yield, and volatility used to determine the fair value of the 2030 Senior Secured Notes.

•With the assistance of fair value specialists, we developed an independent estimate of the fair value of the 2030 Senior Secured Notes and compared our estimate of fair value to management’s estimate.

•We evaluated the sufficiency of the disclosures related to the fair value measurements of the 2030 Senior Secured Notes in the financial statements.

/s/DELOITTE & TOUCHE LLP

San Francisco, California

March 4, 2026

We have served as the Company’s auditor since 2018.