ESS Tech, Inc.

ESS Tech, Inc. (NYSE: GWH) is a long-duration energy storage company that entered the public markets in October 2021 through its merger with ACON S2 Acquisition Corp., a blank-check vehicle sponsored by ACON Investments. The company develops iron flow battery systems designed for commercial and utility-scale energy storage applications, placing it squarely within the clean energy and energy storage sector. ESS Tech filed an 8-K with the Securities and Exchange Commission on October 14, 2025, under accession number 0001819438-25-000057, and continues to trade on the New York Stock Exchange. For complete filing history, sponsor profiles, and deal analytics on GWH and hundreds of other SPAC transactions, sign up for full data access at SpacDesk.