Long considered a linchpin in normalizing the legal marijuana trade, the federal government has issued new guidelines clarifying how banks can provide鈥�

Voters in Washington and Colorado just approved measures legalizing marijuana for recreational use. But businesses that want to sell marijuana in those states will face a problem: No bank wants to do business with them.

In the year since Colorado made recreational marijuana legal, pot has become a billion-dollar business in the state. And some growers are on a serious mission to make it legitimate and mainstream.

As more U.S. states approve marijuana for medical or recreational use, the price for pot growers in Mexico is falling. This could change the business model for narcotraffickers as well.