for now in 2018 I suggest you can invest and buy as many XRP coins as you can because I see this year there will be a good development from XRP maybe the price can go up again and can be very expensive so you should be able to prepare assets you are XRP.
I bought some XRP last year. and this year they drop 60% less. I bought each for 1$ and now that is 0.4$. so I am at lost at the moment. I don't think it'll increase very soon. so my investment is locked until it recovers. and if I sell it now. I'll be in 100% lose.
I should better invest in the real cryptocurrencies that are in the top-20, man. The best tokens for me are still Ethereum, DASH, Cardano, TRON, ICON, and Stellar.
Choosing the top twenty is a great choice because we can get many lists of coins that we can buy in the exchanges. I think you can choose the cheap coin and middle coin and many coins are profitable in shortly. Cardano, tron, xrp, stellar, xem, iota, tezos, vechain, and dogecoin is the low coin price. Eos, neo, etc, omg is the next coin price which less than $20. And you can see that you have a big coin list that you can buy but always makes analysis before you buy.