10 to 50 is about a 400-500% return, which is not a lot in crypto terms. What you should keep away from is BTC and ETH because these coins are unlikely to deliver such great performence. Good candidates in my opinoin are the top five coins, anything in the top five-ten has good potential to double or triple in value. Anytime you go beyong the top ten coins you increase your chances of having a better return but at the same time you risk on being wrong and losing all of your investments. 2018 overal will be a great year because it will most likely attract the biggest publicity and everyone will want to get involved in BTC and everyone will eventually learn about other options and altcoins. Considering that I think you can't go wrong with NEO, XRP, LTC and such coins.