We don't know what is the real reason of the falling value of bitcoin but as you said i think just more like that. It basing on the stocks which is the demand and supply. Crypto was almost same with stock market and correct me if im wrong that if stock market fall crypto was also fall this is base on my observation.
indeed, between the crypto market, stocks, forex, commodities have similarities in the market, but I do not agree that if the stock market falls, crypto also falls, because both have different investors