https://amp.reddit.com/r/Bitcoin/comments/7cefom/roger_ver_just_sent_25k_btc_to_bitfinex/
True, this was certainly market manipulation at work, but the coins moving didn't prompt the drop itself. It came with massive social media FUD and a mempool spam attack. That was a confirmed case of a Bitcoin whale trying to bring down Bitcoin with his friends and failing. That suggests it's much easier to do in theory than in practice.
I would like to know where he got his data. I know that there is market inequality, but I always thought it would be impossible to precisely quanitify because people can use multiple wallets with no traces of each other.
They conveniently forgot to mention that while Roger Ver is still holding Bitcoins, he's rooting for Bitcoin Cash now.