Last March, bitcoin traded at around $1,000 a coin. Later in December, it was more than $19,000. This week, it's back around $11,000.
Some people are betting that in 2050 — or whenever they are more gray-haired than today — it'll be worth a lot more.
"I don't want to be a loser in the future," said Leya Yusupov, a 37-year-old mother of two who lives in Queens, New York. Last year, she invested 15 percent of her retirement savings in cryptocurrencies. "Some people think I'm crazy."
She's not alone.
Six percent of savers say they would consider using cryptocurrencies as an investment option for their retirement plan, according to a recent survey by Auctus, a platform for retirement planning. Fourteen percent said they were unsure, but interested in the idea. Auctus surveyed more than 500 people in the U.S., ages 18 to 44.
Chris Kline, chief operating officer at California-based Bitcoin IRA, said about 4,500 people have signed up for its retirement accounts since it opened in 2016.
Type into Google, "bitcoin IRA" and you'll see a torrent of advertisements. But proceed with caution: These accounts come with heavy fees and risk.
Douglas Boneparth, president and founder of Bone Fide Wealth, said he worries the talk about bitcoin IRAs will make people overestimate how "normal" it is to invest in cryptocurrencies.
"It makes it look more appealing to everyday people," Boneparth said. "For most people who have an IRA, they're in no position to be investing this way. Adding that kind of risk doesn't coincide with most people's desire to get to retire soundly."