With recreational use set to become legal next year under Proposition 64, cannabis sales in the state are expected to top $7.5 billion in 2020, up from about $3.3 billion last year, according to data provider New Frontier and cannabis investor network Arcview Group. But while Proposition 64 broadened the legal use of pot, it did nothing to relax banking regulations. “It left significant questions unresolved,” California Treasurer John Chiang said. “How do you handle the taxation of cannabis dollars and the banking of billions of dollars of transactions that are going to take place here in California?” (See also: State lawmakers group endorses descheduling of cannabis with eye on banking)