High-frequency trading - How Banks Are Making Their Billions at Your Expense

[jeffrey]

It's the hot new thing on Wall Street, a way for a handful of traders to master the stock market, peek at investors' orders and, critics say, even subtly manipulate share prices.

It is called high-frequency trading--and it is suddenly one of the most talked-about and mysterious forces in the markets.

Powerful computers, some housed right next to the machines that drive marketplaces like the New York Stock Exchange, enable high-frequency traders to transmit millions of orders at lightning speed and, their detractors contend, reap billions at everyone else's expense...

Stock traders find speed pays, in milliseconds - CNET News

[Joan.of.the.Arch]

And to supplement, I heard this on public radio yesterday (transcript with link to listen on upper right corner):

Is high-frequency trading fair and safe? | Marketplace From American Public Media