Popular ETF's of Marijuana ETF List (2/5): Returns, Fund Flows, Expenses - Marijuana ETFs invest in companies that:Grow, distribute or sell marijuana. Research the medical uses of marijuana, such as those in the pharmaceutical and biotech industries.Have significant exposure to marijuana stocks, such as those in the alcohol and tobacco industries.. Popular ETF's of Marijuana ETF List (2/5): Returns, Fund Flows, Expenses