CNBC's Jim Cramer said Thursday that he doesn't blame investors for buying into the bitcoin frenzy, but once again he warned that the digital currency's run could end badly.

Earlier this week, Cramer said the cryptocurrency was a pure gamble, and those interested in it should just go to Vegas.

Bitcoin rocketed even higher Thursday morning, crossing the $15,000 mark just 10 hours after topping $14,000, according to industry site CoinDesk. The cryptocurrency, which some market participants have warned is a bubble, has surged more than 1,800 percent this year.

"There's seems to be a level of hoarding," Cramer told "Squawk Box." "People who are owning it aren't flipping it."

"This does feel like it has broken out and it's on liquid oxygen and it's going somewhere," Cramer said. "And I don't blame anyone for wanting to own it because it's a fun ride. And I don't want to talk about when the party is going to be over because maybe the thing is going to Mars. Maybe the thing is going to Jupiter."

"But I do want people to understand that there are mechanics behind this thing that make it so there is no sellers. And if there are no sellers, then it is parabolic," said Cramer, host of CNBC's "Mad Money."

On "Squawk Box" Thursday morning, BK Capital Management founder Brian Kelly, a portfolio manager of a digital currency hedge fund, disagreed with Cramer, saying there's plenty of liquidity on bitcoin trading platforms so would-be sellers won't have problems finding buyers.