i think that Stellar - XLM is one of the coins that can reach the ATH again
it does not need to go x30 - x50 like many other coins
XLM is on top 10 coins dude, it's not OP asked to us. He asks which altcoin will be reach ATH out of Top 50 coins, which XLM already on 50 top coin.
Personally it's difficult to predict which altcoin will be pump so high since there are more than 3000 altcoins out there