1.   Although routine in the securities business, payment for order flow has become controversial.

2.   Although this practice, known as payment for order flow, has been a fact of life in the stock market for years, it is new in options.

3.   As spreads have shrunk over the last five years, payment for order flow has also decreased.

4.   As it happens, the first to pay for order flow appears to have been Susquehanna Partners, which had taken responsibility for Microsoft options at the Chicago exchange.

5.   Ascher acknowledges that Interactive Brokers, like most other brokerage firms, accepts payment for order flow.

6.   Ascher says payment for order flow at Interactive Brokers is less of a factor than at most other brokerage firms.

7.   Ban payment for order flow.

8.   Because the companies are so dependent on order flow and capital spending, their stocks tend to be volatile and therefore vulnerable during market weakness.

9.   But while the payment for order flow has clearly made money for brokerage firms, it is not clear if it has cost customers money.

10.   But, since July, payment for order flow has become institutionalized in the equity options markets.