This is only true for long-term investors. Algorithmic traders have no vested interest in whether the underlying business succeeds or fails. They are only the

This is only true for long-term investors. Algorithmic traders have no vested interest in whether the underlying business succeeds or fails. They are only there trying to predict where the wind will blow next. They are quickly in and out of any potentially profitable company; quick to buy "puts" in a momentary time of weakness or "calls" in a time of temporary strength. For algorithmic traders, it is indeed a zero-sum game. For the rest of us "investors", as I like to call it, to distinguish it from trading, there is potential for long-term good.