The current price of Bitcoin is measured on ‘stable’ coins - USDT,USDT… and keeps going up because of the demand.
It can collapse when a small fraction of the BTC owners decide to cash out - sell BTC to get USDT,USDT… and then attempt to convert USDT,USDT… to fiat USD.
To find details on why a collapse may happen check this article -
The danger in the stable coins (thought experiments and the real price of Bitcoin)