BCH is a fork of bitcoin , It used to be popular in 2018 , but seems like lost some of its popularity, If you want to buy that you better buy bitcoin , coz it just follows its chart , and there are much better coins than that in the market these days.
although like that bitcoin and bitcoin cash are very different, the price movement of bitcoin cash can be the same as Bitcoin because the main coin of all cryptocurrencies is bitcoin, so maybe what you say is true but if you want to get a lot of profit then you must be able to buy Another coin that has a lot of price movements that can give you quick profits.