to be honest, in my opinion, the Top 100 coinmarketcap is a profitable altcoin, because the top 100 certainly has a large trading volume and is listed on a large exchange, it's good for altcoin, and it's not wrong to hold it 
Now even in the top 100 there are some problems, still it is better to choose the coins that are higher and carefully study them, before investing in them, personally I am now considering only the top 20.