Meh, I don't think anyone seriously think CSW has access to any quantity of bitcoins (beyond the few that he has mined).
Whatever he did, he presented everything in such a manner that all his sub-whales dived in the well at his one single order (or maybe, a few big bears grabbed advantage of the opportunity and did what they wanted - gave a shot to bulls who went so weak after such statement of dump publicly arrived).
I do think the Bcash and BSVision (ha, love that the Bcash people used this tactic) dumpster fire had some impact (public perception, people perhaps seeing Bitcoin and crypto generally as being vulnerable to forks, people believing nonsense about CSW wanting to destroy the price of Bitcoin, etc).
It wasn't really the belief in utter nonsense of CSV but the fear of Roger Ver shifting all the mining power of BTC.com from mining BTC to BCHABC.
There's also the DoJ investigation into market manipulation (Tether related) and, of course, the crumbling of the ICO market (quite possibly encouraging founders to sell the last bits of their ICO proceeds and reducing demand for bitcoins and Ether from people who might otherwise have been encouraged to buy into ICOs).
Throw in FUD media pieces to add an air of inevitability to it all.
It will pass.
Comparison of big fat BTC wallets with these ICO guys is literally worth nothing as they can all even can't make it down to 20 bn and what we saw was a freefall with all those big wallet holders selling off a big % to swipe off their BTC of markets through fiat.