Energy Vault Holdings, Inc. (the Company) issued an additional $10.0 million aggregate principal amount of its 5.250% Convertible Senior Notes due 2031 (Option Notes) on February 27, 2026. The Option Notes were purchased by Initial Purchasers who elected to exercise their option under the Purchase Agreement on February 25, 2026. This brings the total aggregate principal amount of Convertible Senior Notes due 2031 (Notes) issued to $150.0 million, following the initial $140.0 million issued on February 17, 2026. The Company entered into additional privately negotiated capped call transactions on February 27, 2026, covering the shares initially underlying the Option Notes. These capped call transactions are designed to reduce potential dilution upon conversion of the Option Notes and/or offset cash payments above the principal amount, with a cap price of $8.12 per share. The cap price represents a 100% premium over the Common Stock's last reported sale price of $4.06 per share on February 11, 2026. A portion of the net proceeds from the initial Notes sale was used to redeem $45.0 million in aggregate principal amount of senior unsecured convertible debentures issued to YA II PN, Ltd. on February 19, 2026.