It's hard to predict. Instead I always check out the results of the coins in the past. To keep it simple and clear I only focus on the top 20.
According tot the overview of the last 30days from WorldCoinIndex there are several coins which have shown huge growth: Chainlink25%, Zcash28%, Cardona64%, Ontology34%. Ethereum has a growth of 25% in the last 30days. Besides Ethereum there are still a lot of interesting altcoins.