> However, a dark cloud remains: market data suggests that 70 percent of U.S. equity trading is now executed by high-frequency trading firms

Is it just me, or was this one of the scarier statements in the article? High frequency trading does not seem to add anything, it's not a market instrument to balance anything. It's more like gambling with the odds slightly in your favor.

Oh course, I'm a laymen when it comes to high frequency trading and might totally wrong.