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?
I dont think it will take much time or we will have to wait so long, I know bitcoin is the crypto currency that changes the price because we recently have experienced as in 2016 price was down then it starts bull and price was higher in 2017 but the same done in 2018 price was down and now in 2019 price is rising rapidly again so I think you really did well if you invested your money in bitcoin you will be safe in future.