It actually bitcoin can really be trusted even for how many huge falls happen but still it bring back its price into good. Definitely, no worries even though we just invest only for Bitcoin cause it have that assurance unlike if we invest with altcoins. But we want more coins to invest with, I suggest to invest among the top 10 coins in the market.
Remember that bitcoin price or market operates in a cycle, so it you invest on it then you have to wait minimum 4 years to see your gains. 4 years because of the block halving. So the question is, do you have the mental resiliency to wait for that long if you go all in?