There was an estimated $31 billion worth of cannabis sales in the U.S. last year, the lion's share of which was generated through illegal transactions. As states start to legalize the green stuff, though, analysts at Cowen & Co. forecast a vastly different - and larger - landscape come 2026.

In 2016, the legal side of this industry created $6 billion in sales. By 2026, this is projected to shoot up to $50 billion, relegating the illegal sales that were once worth $25 billion to a relatively insignificant level.