Wall Street’s main regulator is signaling that the Biden era will spell tougher oversight for cryptocurrencies and blank-cheque companies, two of the white-hot market’s most talked-about asset classes.

US Securities and Exchange Commission chairman Gary Gensler on Wednesday told politicians that special purpose acquisition companies and digital coins posed significant policy and investor protection questions. He referred to SPACs, shell companies that list on stock exchanges for the purpose of buying other firms and making them public, as “blank-cheque IPOs”.

The financial world has been anxiously waiting to see how Gensler will steer the SEC at a time when retail investors have helped to drive markets to record highs. Crypto enthusiasts, who had been hoping the regulator would take a more accommodative approach to digital coins, have thus far been disappointed – and on Wednesday they got more of the same.

“I look forward to working with fellow regulators and with Congress to fill in the gaps of investor protection in these crypto markets,” he said in remarks prepared for a House Appropriations Committee subcommittee. He raised concerns about everything from crypto exchanges to decentralized financial platforms.