🚀🎉 Jim Cramer, host of CNBC's Mad Money and former hedge fund manager, reversed his previously bearish stance on bitcoin [BTC] on Tuesday morning, as expected U.S. regulatory approval and the price rose above $45,000 for the first time in 21 months.

"You can't kill this thing," Cramer told CNBC's David Faber. "[Bitcoin] is a technological marvel and people need to start accepting that it's here to stay." The late Charlie Munger, a famous Bitcoin skeptic, was “blindsided by this,” Cramer said.

Cramer's comments contrast with his remarks during the Sam Bankman-Fried trial in early October, when he said he wasn't interested in long-term investing in crypto because "Mr. Bitcoin is going to drop big." Before that, Cramer said he sold most of his bitcoin holdings in 2021 after the Chinese mining crash.

Of course, the former hedge fund manager wasn't exactly bullish on bitcoin this morning, saying not everyone who is long now is doing so for the long haul and suggesting that spot ETF approvals could be a "sell the news" event.

Bitcoin rose above $45,000 for the first time since April 2022 on speculation that the US Securities and Exchange Commission (SEC) will approve a series of spot bitcoin ETFs this week. The agency faces a Jan. 10 decision deadline for several ETF applicants.

💬 We are waiting for your comments! What do you think about the future of Bitcoin? 🤔🚀#bitcoin#cryptocurrency #JimCramer