Marijuana mega-merger goes up in smoke

Cresco Labs, a Chicago-based marijuana producer, and New York-based rival Columbia Care have terminated their $2 billion all-stock merger, which would have created the largest U.S. cannabis company by sales.

Why it matters: This reflects how hard it is for U.S. cannabis companies to do business, despite expanded legalization.

• Congress still hasn't passed a bipartisan bill that would let banks do business with state-legal cannabis companies, leading Mastercard last week to ban debit cards from being used for marijuana purchases.

Related: The companies had planned to divest some assets to Sean "Diddy" Combs for $185 million, but that deal is now off, too.

The bottom line: Both Cresco and Columbia are listed in Canada, and have seen their shares fall more than 50% over the past year.