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.
Many types of coins that have the potential for you to invest today. So don't focus too much on investing Bitcoin for the future because all have the potential to be good in the future. time to look for better coins.