Yes, but it would be nice if he can diversify in Altcoins too, you are saying the same, dont put all your earnings in the same place, but you are advicing him to put all in bitcoin...
With that money, i would diversify like this (if you wanna invest into crypto, that is why you are here, i guess) 20% Bitcoin - 40% Ethereum - 10% Waves - 30% Other tokens.
With a portfolio like this you will make a very good profit in a long-short term.