I've been thinking a lot about this issue. I heard more than once that many are discussing this topic. Is it safe to invest everything in one, two cryptocurrencies? Or to distribute all the money in all the coins available for this amount?
Spread it around a little. If you are going to only invest in a single coin make it Bitcoin. At least that way you get the benefit of getting the coins from any future forks. But even then that's a risk.