>A blockchain likely wouldn't help this issue either- high-speed traders would inevitably be dissatisfied with blockchain latencies and re-invent brokers that abstracted over blockchain transactions at a faster pace.
It's funny you mention that, because that's exactly what's already happened. Major bitcoin exchanges are internally handling matching and settlement for trading BTC<=>fiat, and part of it is because people do high-frequency and algo trading and need the lower latencies and fast execution, and certainly can't wait for confirmations to know if they really bought/sold the BTC.
I don't know if exchanges end up posting the moves of BTC to the blockchain, or if it's all just a big balance sheet internally and BTC only really moves on the blockchain when you withdraw/deposit. Probably varies between exchanges.
It's funny you mention that, because that's exactly what's already happened. Major bitcoin exchanges are internally handling matching and settlement for trading BTC<=>fiat, and part of it is because people do high-frequency and algo trading and need the lower latencies and fast execution, and certainly can't wait for confirmations to know if they really bought/sold the BTC.
I don't know if exchanges end up posting the moves of BTC to the blockchain, or if it's all just a big balance sheet internally and BTC only really moves on the blockchain when you withdraw/deposit. Probably varies between exchanges.