But most of the time you have to do the opposite of what the masses are doing. Now it's time to buy cheap altcoins because bitcoin dominance won't stay that high forever. Financial markets are never rational, especially not when it's a new technology like cryptocoins. The market is overreacting.
If you can Time it well. Yeah buying altcoins when they are this cheap or maybe they will be even cheaper ( but that's exactly the question ) :D
Or do both, buy some now and buy some later. Average down to the bottom.