Ethereum and litecoin are the most risk free coins in the market. We can also add Dash, Monero to this list as well. All other coins have speculative prices.
I agree, especially on litecoin. If we look at historical snapshots of currencies on coinmarketcap, we'll see that litecoin has been around for a really long time. If we take a look at recent years, I would say that ripple, dash, monero, ethereum and for recent times waves have been rather stable and kept growing with time. Others are mostly just too new to judge and predict long-term IMO. The op is asking about 5% profit, I guess it's safe with coins mentioned above.