Trading is exciting, but doesn't completely satisfy the inner nerd. Although, I have tinkered around with trading APIs, and that is a fun idea... Mining is fun though, and it keeps my house warm in the winter!
If you have the capital to invest then I would suggest you buy some ASICs and join with any of the mining pools so you can make some money while keeping your house warm. I wouldn't suggest GPU mining of altcoins because Ethereum switched to POS now all you can do is mine coins that are worthless and hope that their price will shoot up.