Holding too much coins will make your concentration be scattered and even you may miss the opportunity to sell them with the good price if you can't track it regularly
I suggest holding a coin is not too much, it's better to choose coins that have a bright future and have good selling points. so that in controlling growth the price can be meticulous.
we have to be very selective while choosing coins as our assets or portofolio.just take coins/project that we totally understand their plann in future.especially take them some from top cmc.