That said, I don't understand why people keep significant balances in these places. Keep a small amount to trade with and save the rest yourself!
Yeah, that's what I mean.
You can certainly put money in right before you execute a trade, and pull it back out right after. But that introduces significant lag, up to an hour for bitcoin, depending on how many confirmations you wait for, and several days for USD.
Thanks, that's definitely something to consider. I can see it being very inconvenient, though I still agree that the idea of keeping a balance larger than your trade volume in a service like this is hard to fathom.