Maybe you meant Underrated old coins? Because I see almost every potential old coins are in talk of the crypto town, so if you research the market, you will find many old coins are shining and then comes new Defi and Polkadot ecosystem's coins! Old coins like Utrust a coin from 2017, BNB, Chainlink, Cro, VET, ICX, Coti, XLM, ADA, Mitx and many others are doing very well and all the holders are recovering the loss of 2018! I would suggest you have a look at Coingecko for quick findings.