I agree. Even though bitcoin or the whole cryptocurrency market is decentralised, the big investors can still manipulate the market by making big transactions.
It's not new and has been discussed as always.
People that have big money to invest in the market or we call the whales have the power to move the market somehow on the likes of theirs.
If they want to dump the market, they would do it and the usual thing they do is to make a news, a FUD that will make everyone panic and play with their emotion.