v3.25.4
Insider Trading Arrangements
 3 Months Ended
Dec. 31, 2025
shares
Trading Arrangements, by Individual  
Material Terms of Trading Arrangement The following table describes 10b5-1 trading arrangements adopted or modified by our executive officers and directors during the three months ended December 31, 2025:
Name and titleActionPlan TypeDate of adoption of Rule 10b5-1 trading planScheduled expiration of Rule 10b5-1 trading planAggregate number of securities to be purchased or sold
Robert D. Mailloux
Vice President and Controller
Modification
Rule 10b5-1
8/26/20258/31/2026
21,097 stock options and associated sale of shares to cover option exercise costs and tax obligations.
Grace Lieblein
Board Member
AdoptionRule 10b5-111/24/20257/7/2026
7,777 stock options and associated sale of shares to cover option exercise costs and tax obligations.
Ken West
President and Chief Executive Officer, ESS
AdoptionRule 10b5-111/24/20253/31/2027
3,264 restricted stock units and associated sale of shares to cover tax obligations.
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
Grace Lieblein [Member]  
Trading Arrangements, by Individual  
Name Grace Lieblein
Title Board Member
Rule 10b5-1 Arrangement Adopted true
Adoption Date 11/24/2025
Expiration Date 7/7/2026
Arrangement Duration 225 days
Aggregate Available 7,777
Ken West [Member]  
Trading Arrangements, by Individual  
Name Ken West
Title President and Chief Executive Officer, ESS
Rule 10b5-1 Arrangement Adopted true
Adoption Date 11/24/2025
Expiration Date 3/31/2027
Arrangement Duration 492 days
Aggregate Available 3,264