New York Giants linebacker Devon Kennard is good with money. He avoids unnecessary purchases. He even brought his high school car with him to the NFL. When he invests, it's usually in relatively safe, long-term bets, like real estate.

But after bitcoin briefly topped $19,000, the cryptocurrency frenzy infiltrated NFL locker rooms, and Kennard was one of many players in the league who couldn't resist the hype.

"I'm going to be honest, I downloaded Coinbase and put a couple hundred dollars in," he tells CNBC Make It. That was a few months back. In February, bitcoin has plunged alongside global stock markets. Kennard has lost money.

He laughs that off. Luckily, he was prepared for disappointment after hearing what Berkshire Hathaway CEO Warren Buffett had to offer on the topic.

"I can say almost with certainty that they will come to a bad ending," the Oracle of Omaha told CNBC in January.

"Warren Buffett has been right a lot more than I've been right when it comes to finances, so I don't know if I'm going to bet against him," says Kennard.