Here’s a great chart from Nanex, documenting the rise of high frequency trading as fed in by main feeds from more than a dozen major exchanges.

Nanex has color-coordinated the trades as they come in from the different exchanges (PACF, for those trying to understand, is NYSE Arca).

The GIF starts from January 2007 and continues for four years, leaving out the trading seen just last week when a computer glitch at Knight Capital Group erroneously executed trades for more than half-an-hour.

A nice hat-tip to Reuters’ Felix Salmon for pointing us to it.