U.S. Securities and Exchange Commission Chairman Gary Gensler warned that crypto investments can be “incredibly risky” and “continue to be replete” with fraud in an X thread posted early Monday. 

“Fraudsters continue to exploit the rising popularity of crypto assets to lure retail investors into scams. These investments continue to be replete w/ fraud- bogus coin offerings, Ponzi & pyramid schemes, & outright theft where a project promoter disappears w/ investors’ money,” wrote Gensler. 

In the thread devoted to some “things to keep in mind if you’re considering investing in crypto assets,” Gensler also noted that those offering crypto investment opportunities might not be complying with regulations, including securities laws. He warned that investors might not receive key information and “other important protections” related to their investment. 

Since assuming his SEC position in 2021, Gensler has taken a tough stance on cryptocurrencies, which is at odds with some of his past comments. Last year, an old video surfaced where Gensler, then a professor at MIT, said that Bitcoin, Ether, Litecoin and Bitcoin Cash weren’t securities. In September, Gensler told the U.S. House Financial Services Committee that Bitcoin wasn’t a security. 

The SEC is widely expected to start approving spot Bitcoin exchange-traded funds (ETFs) as soon as this week. The ETFs would provide investors with exposure to the digital asset without directly owning bitcoin. So why is Gensler sending a mixed message?

“He just wants to let everyone know approving [the spot ETFs] were not his idea,” Eric Balchunas, Bloomberg ETF analyst, told Unchained in a message. 

Read more: Fee Competition Heats Up Among BlackRock and Other Spot Bitcoin ETF Applicants

UPDATE (Jan. 8, 4:05 p.m. EST): quote and context added in the last two paragraphs.