The idea of coins being undervalued has more to do with their global acceptance and level of work done on their roadmap and all of that as deemed fit by both the community and the users generally, but if I was to point coins I will start with Matic, which is now Polygon. It is highly undervalued.
I don't see Matic undervalued, the fact that MATIC is now in the top 100 market capitalization proves that the price is not undervalued,
usually undervalued coins have a market cap ranking of over 200,
for example like XCASH, one of the undervalued coins because its market cap ranking is still 700,
but the technology they have is extraordinary, it's just that not many people know about XCASH.
You can try to compare between MATIC and XCASH, between the two which coins are undervalued based on technology, price and market capitalization.