[dorkwood]

To me, what he seems to enjoy most isn't the act of making money itself, but the act of getting better at making money. The great thing about having "making money" as your hobby is that the feedback for performing competently is very clear: if you're getting better, your numbers will go up.

The problem with this hobby, and I suspect this is what the author may be sensing, is that the motivation is extrinsic. The rewards come from outside himself. He is forever reliant on an external force for his own satisfaction.

I think the best fit for this guy would be a hobby that is, like his current hobby, based around the mastery of a skill -- something he can practice and see himself getting better at -- but which doesn't require an external rewards system.

The good news is that almost any creative hobby can satisfy these requirements. As for which one to pick? I've found that looking back to one's childhood can be immensely helpful. What amazed you as a kid? What's something you really tried to be good at, but you couldn't quite make it work? It doesn't have to feel like passion yet. It just needs to be a seed. A tiny hint at an activity you might find satisfying eventually. If you give yourself enough time and room to play with that thing, you may get to experience that passion taking hold.