what does volume have to do with profit percentages??? You buy/sell for the specific price. If BTC is going up against any other alt then it's always better to not trade that alt and just hold bitcoin, even if that alt is going up against any other fiat, because it means BTC is going up even more than the alt against that fiat since everything is measured against the fiat... its really not that hard to understand...
RE: Why is always more profitable to trade alts vs BTC, not vs USD