Chris Wattie / Reuters An employee collects cuttings from cannabis plants at Hexo Corp's facilities in Gatineau, Que.

Derek Peterson is worried about Canadian weed. The CEO of California-based marijuana producer and seller Terra Tech is watching the cannabis industry boom north of the border with more than a little apprehension — because he is already seeing the beginnings of an invasion of U.S. markets by Canada's cannabis firms, today the world's largest. "The concern for some of the players is the market will be dominated by Canadian companies, shareholders and banks if we allow too much time to pass," Peterson said by phone from California. With Canada set to legalize recreational marijuana on Oct. 17, Canadian cannabis stock prices have soared, giving these startup firms enormous amounts of money with which to invest in their business.

Meanwhile, U.S. companies, encumbered by the country's continuing federal prohibition, aren't seeing nearly the sorts of valuations Canadian companies are seeing. "They who have capital get to soak up market share," Peterson said, adding that Canadian companies are "capitalizing themselves extremely well and doing arms'-length investments in U.S. markets, locking down branding opportunities and buying players." Peterson figures the U.S. has only a few years to "get its act together" and reform marijuana laws at the federal level, or Canadian companies stand to win the game. "If we don't see something happen in 2019, almost all of us will be takeout targets for Canadian players," he said. "I don't think there's any law that says the U.S. has to dominate every new industry in the world."Cam Battley, chief corporate officer, Aurora Cannabis There's a lot at stake. One recent estimate suggested the U.S. marijuana market could be worth about US$90 billion a year if it were legalized across the country. These forecasts tend to vary widely, but it's clear that giant green fortunes stand to be made. Cam Battley, chief corporate officer at Edmonton-based Aurora Cannabis, thinks there's nothing wrong with Canada being the one to make those fortunes. "When was the last time Canada got to lead the creation of a new industry worldwide?" he asked by phone from Berlin. "As much as I absolutely love the United States ... I don't think there's any law that says the U.S. has to dominate every new industry in the world." In the past year, Aurora's stock price has quadrupled as investors anticipate a major boom in revenue after Canadian legalization. That and its takeover of rival MedReleaf earlier this year has made it the world's largest cannabis company, valued at more than $11 billion. Earlier on HuffPost Canada: Ontarians Will Be Able To Smoke Weed Wherever They Can Smoke Cigarettes

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BLOG: U.S. Border Officials May Already Know About Your Cannabis Use Battley calls Canada's leading role in cannabis an "accidental success story," one that started with the country's Supreme Court forcing the federal government in 2001 to create a mechanism for medical marijuana patients to access the herb legally. The government of the time "did something smart," Battley says — it instituted a licencing system for private marijuana producers, which created a competitive environment for medical cannabis. This was the seed of today's booming industry, Battley says. And today, with the Liberal government legalizing recreational marijuana at the federal level, the world is watching to see what the results will be. "I would say the world trusts Canada to be the leader on this. We're not known for being wild and crazy. We're known for being very good at public policy."

THE CANADIAN PRESS Aurora Cannabis chief corporate officer Cam Battley in Vancouver, B.C., Fri. Jan. 27, 2017.