Well, again, it can happen quite another, again, if you invest in altcoins then you get x2 risks, I would not invest anywhere I would keep only bitcoin
I think it is not the best decision to hold ONLY btc. I would recommend to hold 80% of your investments in such leaders like btc, eth. Because the are
probably with less risk to lose everything and more perspectives. But, another 20% could be used for altcoins. Of course they are more risky but you need to risk sometimes to get fantastic profits.