Basically moving of the coins can be avoided if you keep a stock of BTC and the other coin on both exchanges. But like you said, trading is definitely more profitable if you do it right. One interesting phenomena I have observed is that when the values of other cryptos are goin down, the value of digixdao goes up and vice versa. That is because digixdao is backed by gold. I'll make a post about that soon. But first, I have to observe things more in depth.