Actually it's not too risky if we have considered it very well. But if I become an OP, I might break my money into three parts to buy bitcoin, bitcoin cash, and BNB. I also used all my money for bitcoin, and at that time it was fortunate enough to go up in price. Altcoin is influenced by bitcoin and when bitcoin goes down the altcoin will also go down, so it's the same if you hold bitcoin or some altcoin because the price will go down too.
Bitcoin I totally agree. But why on earth would you buy an altcoin fork of Bitcoin? You do realize that nobody uses BCash except all its own people who of course had more money to spend than others (because of their forks?).
And BNB is not even a crypto. I'd never spend any thought for investing in something like that. BCH and BNB if their owners do something drastic your coin is finished.