Online Broker Survey: Some Brokers Have a Side Business -- Selling Your Trade Orders

An order to buy or sell a stock may be worth a lot more than most investors know.

That's because of payment for order flow -- a common practice in which the firms that actually make the trades pay brokers to send orders their way. Insiders say it's one of the brokerage business' worst-kept secrets.

Or maybe not. Turns out the ones most in the dark about it are customers. ...