ESS Tech, Inc. — Director's Dealing 2025

Aug 29, 2025

SEC Form 3 — Initial Statement of Beneficial Ownership

Issuer: ESS Tech, Inc. (GWH)
CIK: 0001819438
Period of Report: 2025-08-01

Reporting Person: Suhadolnik Kate Eileen (Interim CFO)

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	30186	Direct

Footnotes

F1: Of the reported shares, 23,805 are represented by restricted stock units, or RSUs, awarded prior to the date on which the reporting person became subject to Section 16. An award representing 394 RSUs was awarded on December 23, 2021. The remaining 48 RSUs vest in two equal quarterly installments beginning on August 20, 2025. An award representing 184 RSUs was awarded on February 8, 2022. The remaining 33 RSUs vest in three equal quarterly installments beginning on August 20, 2025. An award representing 821 RSUs was awarded on November 2, 2022. The remaining 128 RSUs vest in two equal quarterly installments beginning on August 20, 2025.

F2: An award representing 5,351 RSUs was awarded on March 13, 2023. The remaining 2,338 RSUs vest in seven equal quarterly installments beginning on August 20, 2025. An award representing 5,867 RSUs was awarded on February 15, 2024. The remaining 4,032 RSUs vest in eleven equal quarterly installments beginning on August 20, 2025. An award representing 18,375 RSUs was awarded on April 13, 2025. The remaining 17,226 RSUs vest in fifteen equal quarterly installments beginning on August 20, 2025.