Hard to say. I don't know enough about the current economics of exchanges. A Currency exchange would typically not be a bank. They would have a lot more in tr

Hard to say. I don't know enough about the current economics of exchanges. A Currency exchange would typically not be a bank. They would have a lot more in transactions than they would have cash on hand. $4M in transactions on $500k cash on hand. They would have little ability to lose a customers money because the customer would have to be in the store when it was robbed. A bank would not have all of its money in a place that could be robbed, so they don't have 100% risk (or 12.3%). So for a bank the insurance is about .2% of transactions. For BTC it would likely be closer to 3% because the systems are audited.