EXHIBIT B

Power of Attorney

The undersigned hereby make, constitute and appoint Edward F. Glassmeyer, with full power of substitution, the true and lawful attorney-in-fact for the undersigned, in the undersigned’s name, place and stead and on the undersigned’s behalf, to complete, execute and file with the United States Securities and Exchange Commission (the “Commission”), a statement on Schedule 13G and/or 13D with respect to the securities of Circle Internet Group, Inc., a Delaware corporation, and any and all amendments thereto pursuant to Section 13(d) of the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder, and any other forms, certificates, documents or instruments (including a Joint Filing Agreement) that the attorneys-in-fact (or either of them) deems necessary or appropriate in order to enable the undersigned to comply with the requirements of said Section 13(d) and said rules and regulations.

Dated: August 12, 2025

	Oak Management Corporation

	By:	/s/ Edward F. Glassmeyer
	Name: Edward F. Glassmeyer
	Its: President

	Oak Investment Partners XIII, L.P.
	By:	Oak Associates XIII, LLC, its general partner

	By:	/s/ Edward F. Glassmeyer
	Name: Edward F. Glassmeyer
	Its: Managing Member

	Oak Associates XIII, LLC

	By:	/s/ Edward F. Glassmeyer
	Name: Edward F. Glassmeyer
	Its: Managing Member

	/s/ Bandel L. Carano
	Bandel L. Carano

	/s/ Edward F. Glassmeyer
	Edward F. Glassmeyer

	/s/ Fredric W. Harman
	Fredric W. Harman

	/s/ Ann H. Lamont
	Ann H. Lamont

	/s/ Grace A. Ames
	Grace A. Ames

	/s/ Andrew Adams
	Andrew Adams

Circle Internet Group, Inc. SCHEDULE 13G