Early last year, cryptocurrency exchange FTX US was setting its sights on a vast pool of money: individual retirement accounts, or IRAs. 

“We have IRAs trading on FTX today, and are making a push to serve this segment,” Nate Clancy, FTX US’s vice president of business development, wrote in a March email to a New Jersey-based investment adviser, a copy of which was seen by Bloomberg News. Americans held more than $11 trillion in IRAs as of last year.