In other markets, some sort of income is "guaranteed" for traders (or salesman), otherwise nobody would do the job. So you are a speculator, and as such, nothing is guaranteed; some markets operate without speculators at all. The word speculator often carries a negative meaning, but that's what you are. So be prepared for heavy market manipulation and intentional misinformation.
Oh, give it up. "Speculating" on the belief Google will go up and thereby going long Google is not the same as "Speculating" on the belief wheat futures will go up and thereby going long on wheat. The amount of people in the world who suffer, are hurt or die from over-speculation in food and energy commodities is significantly more than those that are damaged by equities being speculated on. Is it wrong for people to be able to buy energy futures? Of COURSE not. Is it wrong when that gets taken to the extreme and people all over the world suffer drastically for the profits of a few? Absolutely.