The opportunity in the bullrun is for all the projects that really have potential and deliver value to the crypto community. And we have new projects on Binance, on Cardano and Polkadot, they are all receiving attention, with many users, the token price will definitely increase in the near future.
But as you say, of the biggest gainers, most of them were those that existed before 2018. I think of a few reasons:
+ Their popularity and popularity;
+ The existence of ATH in 2017-2018, causing the community to expect that those tokens can hit that ATH again;
+ Reliability: investors trust old projects, they fear new projects with smart contract problems or just scams.