The fight between two big groups who've once been supporters of BTC - Roger Ver and Craig Wright (and his underground partner Calvin Ayre) about what to mine and which one to support (Craig came with BSV Bitcoin Satoshi's Vision concept whereas Roger had been supporting his very founded coin BCHSV). Craig warned publicly through media that if his coin doesn't get sufficient hashrate, he'll then need to buy more power for which he won't hesitate to drop BTC down even under $1000 and the sudden move of BTC from 6200 straight down to 5700 in a matter of hours shook the whole market due to which investors lost their confidence in crypto sphere and we're seeing the most awaited bloodbath in the history of crypto that swiped away more than 40 bn in just one day.
Meh, I don't think anyone seriously think CSW has access to any quantity of bitcoins (beyond the few that he has mined).
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). 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.