When Canadian cannabis company Tilray Inc., announced last week it had received permission from the United States Drug Enforcement Agency to export cannabis to California for a medical study, it’s stock price started rising so quickly that trading was halted multiple times.

Tilray is one of the few cannabis companies publicly traded on the US Stock Exchange and it’s extremely difficult to legally bring cannabis into the United States, so the announcement set off a buying frenzy.

The Tilray stock price was “absolutely crazy,” said Greg James, publisher of Marijuana Venture, “but it shows you how much interest there is in the Cannabis industry.”

Tilray had less than $20 million in revenue in the first half of 2018 but at one point was valued at $11 billion when the stock skyrocketed. “It just became untethered to economic reality.” said Mitchell Baruchowitz, managing partner at Merida Capital Partners in New York.

After doubling in price (a tenfold increase from the price at which it had gone public), the Tilray shares fell back when Representative Matt Gaetz a republican in Florida, questioned why the government was allowing cannabis to come in from Canada rather than offering an American company the chance to supply the medical study.

Tilray spokesperson Zack Hutson responded via an email to MarketWatch saying the company agreed that the U.S. federal government should support the industry, but “in the meantime patients and researchers in need shouldn’t have to wait on quality products to conduct critical scientific and medical research.”

United States federal financial regulations make it nearly impossible for its stock exchanges to list cannabis-related companies. In Canada however, adult-use cannabis will be federally legal as of October 17th, 2018 and the country welcomes marijuana-related businesses to its financial markets.

The Canadian stock exchanges list about 120 companies, and of those, about 100 are listed on the  Canadian Securities Exchange. The market value of the five main players on the Canadian stock exchanges has risen from $4 billion to $40 billion over the last year.

“The Canadian core market doesn’t make sense in any rational way, when you look at stock prices and company earnings,” said Baruchowitz. The recent swings upward are hard to justify he said.

It’s not just private investors putting their money into the new industry . Constellation Brands, the owner of Corona beer has invested $4.2 billion into the Canadian cannabis grower Canopy Growth Corporation.  Coca Cola recently expressed interest in the non-psychoactive ingredient in cannabis as a potential drink additive.

The Tilray stock adventure “has changed the way people think about cannabis stocks,” said Baruchowitz. “Investors can’t turn away from the story and then they start looking for similar returns from other marijuana companies.”