Rise of the machines indeed.
From Nanex via MIT's Technology Review:
A chart shows the ascent of high-speed algorithmic trading, a phenomenon that is unnerving the financial markets.
The animated .gif above shows the rise of high-frequency trading across several U.S. stock exchanges over the last five years. You'll notice that there's relatively little activity in 2007, followed by spikes in activity at the opening and close of the market starting in 2008. And then, sometime around the start of 2010, activity becomes much, much more frenetic and erratic. The image was originally posted by Nanex, a company that provides market data to traders....MORE(if the .gif doesn't operate follow the link to TR for the 2007-2012 action)