The Globe and Mail reports in its Tuesday, May 7, edition that when activist short sellers go public with their bearish views on companies trading on stock exchanges they sometimes get it wrong, but they often get it right, too -- enough times to take note of what they are saying. The Globe's Larry MacDonald writes that if you own a stock they are targeting, you may want to take another peek at your bullish thesis. Short sellers have cannabis stocks in their sights because valuations have outrun earnings and revenues. Reinforcing the bearish thesis is an April 10 report by Kristine Owram of Bloomberg. It suggests Canadian producers could lose their first-mover status as the United States takes steps to legalize cannabis at the federal level within the next two years. Of the United States cannabis suppliers operating in the fewer than 15 states that have legalized cannabis so far, six have already become large enough to claim spots on the list of top-10 producers. In addition, Mr. MacDonald notes that the current premium in Canadian wholesale prices is likely to be eroded by growing supply, and Canada's cold climate gives it a competitive disadvantage in growing cannabis.