Cannabis investor Jason Spatafora is urging investors to short Tilray Inc. (TLRY), claiming that the recent spike in the Canadian pharmaceutical company’s share price is “completely irrational.”

“This is like bitcoin levels, the kind of move Tilray is making,” said Spatafora, co-founder of Marijuanastocks.com, reported MarketWatch. “The market is completely irrational. [Tilray’s] market capitalization is over $4.5 billion. That’s insane. They don’t have as much cash as Canopy or Aurora. It shouldn’t trade at half that valuation.”

Marijuana stocks have continued to surge in recent days, following a report that Smirnoff- and Johnnie Walker-maker Diageo PLC.(DEO) was in talks with at least three Canadian pot companies about buying a stake or forming a partnership.

On Twitter, Spatafora was particularly vocal about Tilray being overbought, claiming that he’d be “shocked” if it still trades over $50 in a week.

Time to buy some more put options or go short $tlry will be shocked if is over $50 in a week pic.twitter.com/PyRnpDXkwQ
— Jason Spatafora (@WolfOfWeedST) August 28, 2018

“$tlry bulls I wouldn’t be celebrating just yet, now comes the realization that this company while a good one, can not justify this market cap... this is pure #Fomo and a tiny float,” he said. “Wait till this gets smashed on a bought deal, if they can find an underwriter...”

Tilray’s shares, which have also been boosted by news of second-quarter revenues nearly doubling to $9.7 million, are currently trading at more than triple the company’s initial public offering price. Tilray went public at $17 in July. (See also: The Amazon of Cannabis.) Spatafora was accused of having a case of sour grapes, to which he replied that he didn't hold into earnings because of speculators.

Actually I sold all my put options by 11am and I crushed it... but I wasn’t going to hold into earnings because I knew it would go up from speculators, so ur free to think what u want. Doesn’t change my bottom line https://t.co/TodPbyPgxc pic.twitter.com/lL7sIB6h15
— Jason Spatafora (@WolfOfWeedST) August 28, 2018

In a separate Twitter post, he suggested that the valuations of Cronos Group Inc. (CRON) and Canopy Growth Corp. (CGC), other big gainers in recent weeks, also look frothy.

Rather than buy these popular stocks, he urged his social media followers to focus on “companies that got beaten up unjustly for opportunities." They include: The Green Organic Dutchman Holdings Ltd. (TGOD), Aurora Cannabis Inc. (ACB), Choom Holdings Inc. (CHOO), GTEC Holdings Ltd. (GTEC), Pure Global Cannabis Inc. (RSL), Aphria Inc. (APH) and OrganiGram Holdings Inc. (OGRMF). (See also: Top Marijuana Stocks to Watch.)