Why it goes down.
Well it completed cycle and its time for new one, this is either extended correction from last cycle, or next cycle is simply direction down.
People still don't grasp fully difference between completely controlled markets as stock and completely free market, which is crypto. In free market you have thing called "natural balance", which bit like law of thermodynamics means that it cannot go infinitely in one direction, but for each cycle up, it requires correction.
Regulated markets are manipulated same way as global economics to pretend infinitive growth, which is why you have inflation from hell right now.
Crypto is pretty much like nature itself in virtual reality. So for healthy growth, you get healthy corrections.