By Kavitha Shastry

Shares of Canadian cannabis company Tilray were halted throughout the last hour of trading Wednesday after the stock rose more than 90 percent and then sharply pulled back.

The first stoppage occurred just before 3 pm ET after the stock hit $300 a share and then dropped $37 in a matter of minutes. Shares were halted four more times during the last hour of trading and fell as low as $151 ー 2 percent below Tuesday's closing price ー before finally ending the day up about 40 percent.

Debra Borchardt, CEO and Editor-in-Chief of marijuana publication Green Market Report, told Cheddar that the volatility was partly driven by short sellers capitalizing on "outsized valuations".

"You can't have one of these charts where the stock is just going straight up without something happening," she said. "If it goes up this hard and fast, it usually comes down very hard and fast. That's why you have the short sellers, and they feel like it's a no-brainer."

The rise of Tilray has certainly been nothing short of spectacular ー the stock debuted on the Nasdaq two months ago at $17 apiece for a market value of about $1.5 billion. At its highs on Wendesday, the company was worth more than $27 billion, eclipsing much more established names like Kellogg, Best Buy, and CBS ー companies that have revenues orders of magnitude more than Tilray.

Investors have been piling into the stock and others in the industry on the heels of a slew of both positive and speculative headlines. Earlier this week Tilray got DEA clearance to import cannabis to the U.S. for a University of California San Diego research study, appears to be paying off. That comes after reports Coca-Cola was teaming up with Aurora Cannabis to make CBD-infused drinks and an investment by Corona-maker Constellation Brands in Canopy Growth.

As a group, marijuana stocks are up about 30 percent since August, according to IHS Markit.

But many market watchers expect there to be big swings. On Wednesday morning Citron Research, known for making bearish bets on stocks, tweeted that Tilray's jump was "beyond comprehension." The firm said, "We are short and will hold a manageable position until rationality sets in."

Shares of Tilray were trading down again after hours but were nevertheless still more than ten times their IPO price.

For full interview click here.