Selection of medical recreational cannabis at a legal retail storegettyIn most US industries, banks help businesses finance their buildings. The lenders also provide working lines of capital for the operations to grow.Cannabis is different. It is tricky for operators to find money due to federal roadblocks.At the national level, cannabis is still illegal. However, 40 states have legalized the drug in some fashion. Uncle Sam mostly looks the other way and lets states regulate their own markets—except when it ...