These three cannabis companies offer different ways to play an industry that's down by 80% from its peak, but showing signs of life.The cannabis sector remains one of the most challenging areas to invest in successfully. The space is volatile, highly regulated, and filled with companies that have yet to demonstrate that they can produce long-term profitability. At the same time, the potential for policy changes, endorsements of cannabis for medical or wellness uses, and renewed investor interest keep the in ...