It is not necessary that if a token/coin has high market capitalization, it means it is worth it. If a token with a total supply of 100 billion gets listed on a shit exchange where you see buy orders set at price $0.0001 and sell orders at $0.01 and if just one buy order happens, it will ultimately bring its market cap to 1 billion USD if coinmarketcap has that token listed there. So this is a subject which needs enough of research to invest and find those good tokens which will give better gains.