The Australian federal government lit a spark under the industry when it announced earlier this year it will be legal to import and grow marijuana in Australia.
In America, marijuana is still illegal under federal law. However, since 2012, eight states have legalised adult-use recreational pot and, over the past two decades, 28 states have legalised the use of medical cannabis.
Marijuana is already a huge industry and, according to some, will be absolutely enormous in coming years. So huge that any self-respecting investor would be mad to miss out. Some have compared it to the liquor industry post-Prohibition.
According to Arcview Market Research, legal marijuana was a $US3.4 billion business in America in 2015 and by 2016 was $US7.1 billion, making it the fastest growing industry in the world. It is expected to triple during the next three years to $US22 billion.
That sort of growth makes the tech industry look positively stagnant.
The excitement around the industry is the stuff of legend. Shares of three of the largest cannabis businesses on the Australian Stock Exchange - AusCann, Zelda Therapeutics and MMJ Phytotech - each grew by more than 150 per cent in the past six months.
Phytotech was the first cannabis stock to list on the ASX in January 2015 to a rip-roaring response - it climbed from $A20 to $A92 in two days, only to retreat back to $A28 when its founder quit two weeks later.
Another ASX-listed stock Stemcell United rocketed from just $A1.30 to $A41 in less than two days, turning the Singapore-based company from a $A5 million company to one with a $A145 million market capitalisation.
All because the company appointed a new strategic adviser - a colourful character known in the industry as "The King of Cannabis" - to help the company "assess opportunities" in the sector.
So with all this hoopla, why wouldn't I want to invest?
Putting my views on recreational marijuana to one side, it just feels like a really hard and risk-laden industry to play in.
While I understand the market opportunity for medical cannabis and the enormous benefits that can accrue to society once a well-regulated and policed industry evolves, it is very early days. As an investor, I'm uncomfortable being an early adopter.
It's a challenging industry because there's no dominant player and it's difficult for any one grower, manufacturer or distributor to gain a competitive advantage over others.
The marijuana industry will always be heavily regulated and monitored; it's never nice being a company shareholder when the rules change at the whim of a regulator.
My final reservation is entirely subjective. Company management is important to me and I'm not sure a CEO of a recreational marijuana business would ever rank amongst my favourites.
Other investors clearly don't share my reservations. They should enjoy the high while it lasts.
