As of September 2018, marijuana use is legal in some capacity in 29 states. This has opened the door for thousands of new enterprises in this industry, from dispensaries to manufacturers of marijuana production equipment to business and legal consultants with an expertise in this field. So, there are lots of companies to invest in.
What makes these stocks attractive, though, is the fact that the industry is relatively new and has the potential for explosive growth, especially in states like Massachusetts where the sale of marijuana has only been legal since January 2018. More states will likely follow this trend, and there's even the chance for federal legalization, similar to the change recently announced in Canada.