I think that the big whales had already exited bitcoins when it was at peak. They are manipulating alt coins now.
Altcoins are anyway susceptible to manipulation. They have low market capitalization, low liquidity and anybody willing to put down some money can try a pump and dump. You need some stomach to hold cryptocurrencies for the long term. It doesn't matter how big whales trade in the interim, because a good coin will definitely appreciate in value in the long term.