I personally would not go all in on any coin... just remember, crypto is very much like the stock market - no one really knows if it is going to go up or down or in between - so my long term position is to never spend anymore on crypto than you can afford to lose
With that being said if you start investing what you can now each month, by this time next year you can have a diverse little crypto portfolio to trade & make $$ with
My biggest turnover was with Collosus coin (COL) (i think its COLX now) 1.2 million coins for less than $5 purchased 4 years ago, currently valued around $11.6k
Right now though, my long terms are ETH - LTC - BTC (which is below $6900 again today, might be a good time to get in if you are waiting to bust a move!)
Best of luck everyone - it can be rough out there but again just remember not to invest what you cannot afford to lose!