I read somewhere that this drop of BTC is due to BTC futures options expiry at 26.02. so if this was the reason and if price does not drop in 30-40k range and cause too much fear, we should see better days for overall crypto since this weekend... Just an opinion and some hope, not advice:)
How futures' expiration act in these cases?
Some are guessing(?) that the drop was planned to cause some panic and then take the advantage with selling as short ..
https://www.cityam.com/bitcoin-price-crashed-here-is-what-comes-next/CBOE uses Gemini exchange as settlement price and at Sunday night UTC there was an warning on socials that big amount of BTC has been moved on Gemini wallet, so in this way they might tune settlement price in direction on shorts. At least I understood that way, and now can not find the text:(