Well, to be fair, the lottery certainly has the highest ROI %. If that's what you're after. It fits exactly where it should on the risk vs. reward scale.

On the other hand, if you say, "I trade stocks for a hobby," you're going to get far less dirty looks than you will with, "I'm a compulsive gambler."

I think a lot more people would be doing this over gambling. They probably just think it's a LOT more complicated to learn than it really is - and by that I mean the process of buying and selling, not the work required to make good choices. A couple of video clips of the trade floor is enough to intimidate practically anyone.