It`s like you are suggesting investing profit you previously made on some risky thing. Profit is profit, it`s money you made and it`s yours to spend it as you like. Suggestion someone what is smart to do with their own money is stupid in my opinion, even with close friends it`s hard to do something like that, you should really know someone good to be able to suggest something that`s suit their personality and wishes.
With profit I make I do many things, sometimes I reinvest it in the same thing, what was profitable once can be profitable second time again. Sometimes I send profit to a safe wallet for keeping in coin I think it`s good for that. Sometimes I just gamble it away, cause I like it!