I invested in mmja (medical marijuna Inc.,phot (grow life), and hemp. These are penny stocks. I doubled my money right after Colorado began selling to all adults Jan 1, 2014. But the stocks went up becuase of the hype, not becuase these companies increased business metrics. After the hype was gone, they dropped in price. PHOT trading was suspended by SEC for weeks for suspected trading issues. After the SEC unsuspended, the stock price dropped in half. So, it's a risky way to make money but start following marijuna stocks daily, read stocks news, and try to get quarterly and annual report to reviews. This is tough cause allot of these companies just started in last fews years. Also in my research I could not find any marijuna industry mutual funds so that option is probably out. Some funds are considering adding a marijuna industry fund but not yet. Good Luck!

Banking and insurance, that's what I would do. FDIC insured banks have been told not to deal with these people and insurance regulators are having a tough time too.

You can also buy some warehouse space in the next states planning to legalize it; just read about what is going on in Colorado.