They don't really. They are just affected by what bitcoin is doing. If bitcoin price is changing they always get dumped. And whenever it is stuck in a fixed price like these days the shitcoins start pumping simply because there is no profit to be made day trading bitcoin at a fixed price like 34k but a lot of profit to be made in shitcoin pumping and as soon as bitcoin starting moving they dump those shitcoins and come back to bitcoin; which is why altcoin always dump when bitcoin moves.