> E.g. if you borrow 1 BTC from someone and then sell it for dollars Why does that guy trust you to return the BTC later? You don't need an exchange per se. B

> E.g. if you borrow 1 BTC from someone and then sell it for dollars Why does that guy trust you to return the BTC later? You don't need an exchange per se. But both people need to trust each other. In the stock market, cleaning houses serve as the central role of trust (and brokerages pass your money/stock to these cleaning houses). ----- It goes like this: if you don't return the stock, the clearinghouse will return the stock. If the other guy doesn't return the money, the clearinghouse makes it whole again. Since the clearinghouse is well trusted, everyone is happy with the trust issue. Otherwise, you have no reason to trust random people on the internet with your $15,000+ bets.