Circle Internet Group, Inc.

1. The restricted stock units were granted on March 2, 2026, and vest over four years in substantially equal quarterly installments, in each case, subject to the Reporting Person's continued service with the Issuer through each applicable vesting date.

2. Represents 56,408 shares of Class A common stock held outright by the reporting person and 237,793 shares of Class A common stock issuable upon the vesting of restricted stock units.

3. Represents shares of Class A common stock held through an irrevocable non-grantor trust, of which the Reporting Person's legal counsel is the sole trustee and the Reporting Person's child is the beneficiary. The Reporting Person disclaims beneficial ownership of the shares of Class A common stock.

4. Each Restricted Stock Unit represents a contingent right to receive one share of Class B Common Stock.

5. The Restricted Stock Units vest in substantially equal monthly installments from July 1, 2025 through January 1, 2027, in each case, subject to the Reporting Person's continued service relationship with Circle Internet Group, Inc. through each applicable vesting date.

6. The Restricted Stock Units vest in substantially equal monthly installments from July 1, 2025 through January 1, 2028, in each case, subject to the Reporting Person's continued service relationship with Circle Internet Group, Inc. through each applicable vesting date.

7. 1/4 of the shares subject to the Restricted Stock Units vested on January 1, 2026 and the remaining portion vest in 36 substantially equal monthly installments thereafter, in each case, subject to the Reporting Person's continued service relationship with Circle Internet Group, Inc. through each applicable vesting date.

8. Each share of Class B common stock is convertible into Class A common stock on a one-for-one basis at the option of the Reporting Person. In addition, each share of Class B common stock will convert automatically into Class A common stock on a one-for-one basis upon any transfer of such share, except for certain permitted transfers described in the Issuer's Amended and Restated Certificate of Incorporation. Shares of Class B common stock do not expire.

9. Represents shares of Class B common stock held through an irrevocable grantor trust, of which the Reporting Person is the sole trustee and the Reporting Person is beneficiary. The Reporting Person is entitled to annuity payments from the trust, with any remaining assets to be distributed to the Allaire 2025 GRAT Remainder Trust, of which the Reporting Person's children are beneficiaries. The Reporting Person disclaims beneficial ownership of the shares of Class B common stock except to the extent of his pecuniary interest therein.