As you may know, the position at the coinmarketcap ranking is not permanent, any coin/token can be at the top at any time, and know one/token has been able to occupy from the number two position permanently. Apart from bitcoin at the king, no altcoins has maintained a permanent position even ethereum.
Now, as for cardano investments, it very obvious that Ada is potential coin for investment especially considering the developmental progress the team has embarked upon, like the smart contract addition, current partnership deal chainlink etc.
Cardano is still an investment opportunity for both new and existing investors any time.