How would an algorithm react to / speculate on the most recent news of, say, the VW pollution-cheating fiasco? What about embargoes or war breaking out between certain countries?
An algorithm parsing the aggregate reaction of mostly non-experts, mostly to news delivered over relatively slow mainstream media channels, is going to be much slower than a human hearing the investor briefing and hitting the "sell at any price" button.
http://www.wsj.com/articles/tweets-give-birds-eye-view-of-st...
http://tradethesentiment.com/