Shares in marijuana company Tilray Inc. went on a wild ride -- surging by more than 90 per cent then briefly dropping into negative territory and rebounding -- one day after the licensed producer said it got approval to export medical cannabis from Canada to the U.S. for a clinical trial.

The stock closed at more than US$214, up 38 per cent, after being halted five times within one hour.

The drastic swings in the stock follow a nearly 30 per cent jump on Tuesday after the Nanaimo, B.C.- based firm announced it got the green light from the U.S. Drug Enforcement Administration to export cannabis in capsule form to a researcher at a university in the U.S., where the drug is still illegal at the federal level.

Tilray will be exporting to the University of California San Diego capsules with two active ingredients -- cannabidiol and tetrahydrocannabinol, better known as CBD and THC -- extracted from the cannabis plant for a clinical trial as a potential treatment for essential tremor, a neurological disorder that causes uncontrollable shaking. The one-year trial is scheduled to begin in 2019.

On top of being positive for the sector, the clinical trial supports Tilray's medical cannabis prospects as it competes with Smiths Falls, Ont.-based Canopy Growth in an intellectual property-arms race, said Cowen analyst Vivien Azer in a recent note.

"(The) news is a positive for both TLRY and the broader cannabis stock universe, as additional medical applications and improved government support add another domino to future legalization in the U.S.," she said in a note on Tuesday.

While cannabis is legalized in several states for recreational and medical use, it remains a Schedule 1 drug under U.S. federal law.

Tilray shares shot up over US$230 just after the trading day began on Wednesday, but quickly backed off.

However, by late afternoon, surged to US$300, up 94 per cent from its previous close of US$154.98. Roughly an hour later, the share price slipped to US$151.40 before climbing back up to close at US$214.06, up 38.12 per cent. Tilray's stock was halted five times between 2:52 p.m. and 3:48 p.m. -- all volatility trading pauses.

Tilray completed its initial public offering in July with its shares priced at US$17 per share.

The licensed producer's market capitalization was roughly US$19.9 billion at close.

Canopy Growth, which had been the largest cannabis company based on market value until Tilray surpassed it this week, had a market capitalization on Wednesday of $11.28 billion on the Nasdaq at close.