What exactly are the requirements for building an exchange? - Large amounts of capital, for one. - If in the US, a banking license; Offshore, not a requirement. - I'm not clear on how exchanges like coinbase source their crypto. Probably a totally stupid question but what happens to the cash I give coinbase after they go off to exchange it for say Ethereum? Do they have a network of whales that are selling them crypto for fiat for some sort of premium? Do they just hold crypto and exchange at market rates (which presumably exposes them to large potential loses)? I know they're linked to GDAX but this still doesn't explain how they source their currency initially.