i don't trust things i "read online" and neither should you. for example in this case was it really one whale selling 3600 bitcoin or was it 3600 bitcoin sold in that period by traders tanking the price? there is a big difference here. looking at the charts it is a sharp drop but if you zoom in to minute intervals you can see that it is traders panic selling which is a normal thing specially when they are using bots with stop loss orders and watchers to execute them so when a drop happens below their threshold their bot kicks in and starts selling so the big drop shapes up sharp like this.

this was a manipulation though because it started by a whale(s?) selling down to that threshold to trigger the sharp drop so that their shorts could be filled. but the size was nowhere near 3600BTC from what i can see.