Circle, the company behind the world’s second-largest stablecoin USD coin, has been subpoenaed by the US Securities and Exchange Commission.

4 of Circle, the SEC issued an “Investigation Subpoena” from its Enforcement Division in July.

Circle, behind Stablecoin USDC, stated that upon receiving the request, it will work fully with the regulator:

“Additionally, in July 2021, we received an investigative subpoena from the SEC Enforcement Division requesting documents and information on specific holdings, customer programs, and operations. We cooperate fully with your investigation. “

The Circle profile is part of a plan to go public through a merger with Concord Acquisition Corp via a special purpose vehicle, valued at $ 4.5 billion.

CIrcle made a similar statement in an August filing as part of an SEC investigation into the activities of its former subsidiary Poloniex. That same month, Circle agreed to pay the SEC over $ 10 million in fines for allegations against Poloniex, which operates as an unregistered cryptocurrency exchange.

Related: Coinbase is lifting requirements for stablecoin USDC backed by the US dollar

In late July, Circle released a report that found 61% of USDC’s reserves are held in cash and the remainder in commercial papers, treasury and bond accounts.

In early September, the SEC threatened to sue the Coinbase member of the USDC Issuance Center over a proposed loan product that would earn interest among a select number of USDC holders.