In my opinion, you better invest in both Ethereum and Ripple as they are already stable in the market.
Both of them are ok for a long-term investment.
Putting all eggs in one basket would be very risky so we better to have multiple coins.
At least you will have a conservative approach when it comes to trading.
You better to read the news about the forecast so that you will know what new coins will pump up and this will serve as aggressive approach in trading. So we better so invest now since the price is still low and wait for the increase by the following month as speculated.