HFT

A nice explanation for how high frequency trading makes its outsized gains:

Trading in Milliseconds: When Correlations Break Down
http://jaredbernsteinblog.com/trading-in-milliseconds-when-correlations-break-down/

In the comments (most of the comments on his blog are intelligent) is another nice analogy:

http://jaredbernsteinblog.com/trading-in-milliseconds-when-correlations-break-down/#comment-2146150:

It would