https://www.reuters.com/article/us-usa-cftc-subpoena/u-s-regulator-subpoenas-cryptocurrency-platforms-bitfinex-and-tether-source-idUSKBN1FJ2ZK

The U.S. derivatives regulator has sent a subpoena to two of the world's largest cryptocurrency platforms, a person familiar with the matter told Reuters on Tuesday, as watchdogs globally increase their scrutiny of the emerging asset class.