The roller-coaster ride of B.C.'s most volatile cannabis stock took a steep dive downward today.

Nanaimo-based Tilray's share price fell 8.94 percent to close at US$109.05.

The company's market value is US$10.16 billion, down from US$11.15 billion at yesterday's close.

This came a day after Politico reported that Canadian cannabis-industry workers could receive lifetime bans on visiting the United States if they're stopped at the border.

In July, Tilray became the first Canadian licensed producer of cannabis to launch an initial public offering on a U.S. stock exchange.

Its nine million class 2 shares were initially priced at US$17 on NASDAQ. They're now trading at 6.4 times that amount.

Other cannabis shares fared far better today after taking a beating yesterday.

Canopy Growth Corp. was up 7.4 percent to close at $61.52.

This rise enabled it to supplant Tilray as the country's most valuable cannabis company.

Canopy Growth is worth $14.06 billion, whereas Tilray, in Canadian funds, is worth $13.24 billion.

Another Canadian cannabis producer, Aphria Inc., recovered most of its losses from the previous day, rising 13.01 percent to close at $19.55. Its market value is now $4.54 billion.

Cronos Group's gain was more modest—up 3.21 percent to close at $13.52. Its market value is $2.39 billion.

Aurora Cannabis shares went up by 2.89 percent, closing at $8.54. Its market value is $8.13 billion.