"That's where the money is, if there's a will to continue legalising markets," Bornold said. "But if the wind turns, that gigantic market will close as fast as it opened."
Local stocks have also got caught in reefer madness, even though Sweden will probably be among the last countries on Earth to legalize marijuana. Heliospectra AB, a maker of advanced lighting systems for plants that trades on Stockholm's alternative market for smaller companies, soared 143 percent in the first two weeks of the year and is up 39 percent year-to-date.
"Heliospectra became involved in the rush due to the so-called Klondike thesis, that is, it's not the gold diggers that make the money, but the people selling the spades," Bornold said.
While the start of the year was exceptional, Bornold predicts the craze will cool. In total, about 50,000 Swedes traded in cannabis shares on Nordnet and Avanza during January, according to Bornold.
"Trading in these shares will most likely continue, but not at this level, we just can't have more people trading in cannabis shares than in Volvo shares," he said. "It's interesting that so many Swedes are prepared to invest in cannabis companies while very few according to polls want to legalise cannabis in Sweden. There doesn't seem to be a problem in making money from it."