FORM10-Q ☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June30, 2026 OR ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Commission File No. 001-38823 HYLIION HOLDINGS CORP. (Exact Name of Registrant as Specified in Its Charter) Indicate by check mark whether the registrant (1)has filed all reports required to be filed by Section13 or 15(d) of the SecuritiesExchange 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. YesNo☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submittedpursuant to Rule 405 ofRegulationS-T(§232.405 of this chapter) during the preceding 12 months (or for such shorter period that theregistrant was required to submit such files). YesNo☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer,anon-acceleratedfiler,a smallerreporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smallerreporting company,” and “emerging growth company” inRule12b-2ofthe Exchange Act. If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined inRule12b-2ofthe Exchange Act). Yes☐No Securities registered pursuant to Section 12(b) of the Act: HYLIION HOLDINGS CORP.FORM10-Q FOR THE QUARTERLY PERIOD ENDED JUNE30, 2026TABLE OF CONTENTS PART I. FINANCIAL INFORMATION Item1.Financial Statements (Unaudited)1Condensed Consolidated Balance Sheets1Condensed Consolidated Statements of Operations2Condensed Consolidated Statements of Changes in Stockholders’ Equity3Condensed Consolidated Statements of Cash Flows4Notes to Condensed Consolidated Financial Statements5Item2.Management’s Discussion and Analysis of Financial Condition and Results of Operations13Item3.Quantitative and Qualitative Disclosures About Market Risk26Item4.Controls and Procedures26 PART II. OTHER INFORMATION Item1.Legal Proceedings27Item1A.Risk Factors27Item2.Unregistered Sales of Equity Securities, Use of Proceeds, and Issuer Purchases of Equity Securities27Item3.Defaults Upon Senior Securities27Item4.Mine Safety Disclosures27Item5.Other Information28Item6.Exhibits29 PART I. FINANCIAL INFORMATION HYLIION HOLDINGS CORP.UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS(Dollar amounts in thousands, except share and per share data) HYLIION HOLDINGS CORP.UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS(Dollar amounts in thousands) HYLIION HOLDINGS CORP.NOTES TO UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS(Dollar amounts in thousands, except as separately indicated) Note 1. Overview Hyliion Holdings Corp. is a Delaware corporation headquartered in Cedar Park, Texas, that designs and develops the KARNOPower Module for stationary and mobile applications and provides research and development (“R&D”) services. References to the“Company,” “Hyliion,” “we,” “our,” or “us” in this report refer to Hyliion Holdings Corp. and its wholly owned subsidiary, unlessexpressly indicated or the context otherwise requires.TM The KARNO Power Module is a complete, fully integrated, enclosed, fuel agnostic power generating solution, including balance ofplant systems such as cooling, controls, fuel, and air handling, that generates electricity on command in stationary power generationapplications powered by KARNO Cores. The KARNO Core is a heat-powered generator that uses linear motors in a four-shaft systemto generate electricity. Heat is generated through the flameless oxidation of fuels while achieving near zero emissions withoutaftertreatment systems. Note 2. Disposals In November 2023, the Company initiated the wind-down of its powertrain business (the “Plan”), the majority of which activities werecompleted in 2025. See Note 2 to the consolidated financial statements in our 2025 Annual Report for additional information. TheCompany has not accounted for the impacts of the Plan as a discontinued operation as the underlying intellectual property has not beenabandoned or sold. The Company recognized net (benefits) costs related to the Plan, consisting primarily of recoveries from sales ofassets, of $(0.3) million and $(0.3) million during the three months ended June30, 2026 and 2025, respectively, and $(0.7) million and$1.1million during the six months ended June30, 2026 and 2025, respectively, which are included in exit and termination (benefits)costs in the condensed consolidated statements of operations. Remaining accrued lia