What I find most interesting about Coinbase is that they quote your selling exchange rate the moment you place a sell order. If I click "sell" right now, they lock in the $13,000 exchange rate or whatever it is. The amount that shows up in my bank days later is exactly what they quoted at the time I placed the sell order. When people start selling off, this policy is either going to drive them to bankruptcy or create a lot of unhappy customers.
That's not a symptom of a problem - the time delta of settlement with you has no relation with the time delta of them balancing their position. It's just as big bank forex deals work; if a customer of a big bank sells $100m euros for dollars in their bank, the bank (most banks who don't want to play market maker) will often get a matching deal within minutes, but the deal can often be actually settled on the next business day or the day after that.
I don't understand why it's a problem. Coinbase received $13,000 from User A and they pay it to User B. Why will Coinbase go bankrupt or customers be unhappy?
