A Moral Problem with Trading the Stock Market?

I received a comment on YouTube which implied that being a trader in the stock market (or any financial market for that matter) is a problem when it comes to morality. While this person was not very specific on 'why' they felt this was the case, I'm actually going to take the opposite side of the debate and argue that being a trader in the market IS the moral thing to do. I believe I present a strong case for how those of us who do trade are actually doing the morally right thing.