A top U.S. regulator said on Tuesday there is no way to police all cryptocurrency fraud because there is so much, though her agency is working on several big cases. Christy Goldsmith Romero, one of five commissioners at the Commodity Futures Trading Commission (CFTC), said cryptocurrency cases account for about 20% of the agency's portfolio, including recent civil cases against the exchanges Binance and FTX. "There's just a lot of fraud in the space," Goldsmith Romero said at a white collar crime conference at the New York City Bar Association.