"The prices of cannabis stocks today feel like bitcoin and ethereum did in December of last year," Novogratz, a closely bitcoin evangelist, said Thursday at the Yahoo Finance All Markets Summit.

Former Goldman Sachs macro trader Michael Novogratz sees a lot in common with the cannabis craze and last year's record-setting crypto gains. For that reason, he's betting against it.

This week, as pot stock Tilray jumped 50 percent, Novogratz said he "tried real hard" and found a "cool way" to short it.

"The companies trade up to $28 billion on almost no revenue," he said. "If I was long them, I'd sell them and if you're a speculator, I'd get short them."

Bitcoin, which Novogratz has been a vocal investor in, similarly shot up by double-digit percentages last year. The cryptocurrency has plummeted 66 percent since its high, according to data from CoinDesk.

Novogratz is hardly the only one betting against the cannabis craze. Data from S3 Partners show that short interest in Tilray is around 3.5 million shares, up from about 2.5 million late last month.

This week was an expensive time to bet against the stock. Fees for borrowing Tilray stock, which you need to do to short it, were between 500 and 700 percent, according to S3's managing director of predictive analytics Ihor Dusaniwsky.

Still, Novogratz is optimistic on the industry long-term and predicted the entire "cannabis business is going to grow, and it's going to grow relatively rapidly."