it's definitely more than a side hobby. I probably put about 20 hours/week while also working 40 hours my normal work. I've also had stints where I worked on trading full time (6 months+ stretch). That's why I sent my follow up comment on "is it worth it". If your serious about trading, you need to understand the level of commitment. Also add the stress levels from when you inevitably hit bumps in the road (my large loss was a huge damage to my psyche at the time). It's not for everyone.

To answer your question, I started in equities but moved to commodity and index futures/options.