From my article on Cryptopedia

IRAs can own bitcoin and other cryptocurrencies. Crypto IRAs offer many advantages, the first and foremost reason being that the gains made on selling crypto with an IRA are generally not taxable. And if you have a Roth IRA, the profits come out entirely tax-free at retirement (age 59 ½). For traditional IRAs, the gains are tax-deferred, and owners are taxed as they draw funds out at retirement. These tax outcomes apply to Roth IRAs and Traditional IRAs when buying and selling stocks or mutual funds as well as crypto.

Read the article from Cryptopedia here.