ESS Tech, Inc. Receives Continued Listing Standard Notice From NYSE (Form 8-K)

ESS Tech, Inc. Receives Continued Listing Standard Notice From NYSE

WILSONVILLE, OREGON - June 15, 2026 - ESS Tech, Inc. ("ESS," or the "Company") (NYSE:GWH), a leading manufacturer of sustainable energy storage solutions, today announced that on June 9, 2026, it received notice (the "Notice") from the New York Stock Exchange (the "NYSE") indicating that the Company did not satisfy the continued listing standard set forth in Section 802.01C of the NYSE Listed Company Manual because the average closing price of the Company's common stock was less than $1.00 per share over a consecutive 30 trading-day period. As of June 8, 2026, the 30 trading-day average closing share price of the Company's common stock was $0.98. The Notice is a notice of deficiency, not delisting, and does not currently affect the listing or trading of the Company's common stock on the NYSE.

In accordance with applicable NYSE rules, the Company intends to notify the NYSE within 10 business days of its intent to regain compliance with Rule 802.01C and return to compliance with the applicable NYSE continued listing standards. The Company can regain compliance at any time within a six-month cure period following its receipt of the Notice if, on the last trading day of any calendar month during such cure period, the Company has both: (i) a closing share price of at least $1.00 and (ii) an average closing share price of at least $1.00 over the 30 trading-day period ending on the last trading day of the applicable calendar month.

The Company intends to remain listed on the NYSE and is considering all available options to regain compliance with the NYSE's continued listing standards. The NYSE notice has no immediate impact on the listing of the Company's common stock, which will continue to be listed and traded on the NYSE during such cure period, subject to the Company's compliance with other NYSE continued listing standards.

Furthermore, the Notice is not anticipated to impact the ongoing business operations of the Company or its reporting requirements with the U.S. Securities and Exchange Commission ("SEC").

About ESS Tech, Inc.

ESS (NYSE: GWH) is the leading manufacturer of long-duration iron flow energy storage solutions. ESS was established in 2011 with a mission to accelerate decarbonization safely and sustainably through longer lasting energy storage. Using easy-to-source iron, salt, and water, ESS iron flow technology enables energy security, reliability and resilience. We build flexible storage solutions that allow our customers to meet increasing energy demand without power disruptions and maximize the value potential of excess energy. For more information visit www.essinc.com.