It seems many people are speculating the rise of BTC and therefore are transfering value from alts to BTC. But if you want BTC, buy it with FIAT! Fresh new funds are needed on the market! You are dumping alts making prices dump hard and maybe are speculating you will be able to buy more of the alts later on, but what idiot will selll it to you at that dumped price?? So if you want BTC, buy it with FIAT or at least don't expect to buy back more of the alts for cheap!
A lot of people will still do that and wouldn't care on dumping any coin. That how the market goes and works and we couldn't stop those people from doing it.