Trading on the Amex

Members of the American Stock Exchange may execute orders on the trading floor swiftly, with reliability, accuracy and transparency.


Member firms may route orders directly to the Exchange's trading floor through the Common Message Switch (CMS). After performing specific validation checks, CMS routes the orders to the Amex Order File (AOF), which retains order details and directs orders to the New Equity Trading System (NETS), Amex Options Display Book (AODB), Automatic Execution (Auto-Ex), or the firm's floor broker through the Booth Automated Routing System (BARS).

Developed with the auction market trading process as their foundation, these systems allow brokers and specialists to perform their functions in an extremely efficient manner, while virtually eliminating the handling of paper on the trading floor. Just as a specialist can be responsible for more than one stock, option, ETF, or structured product, these systems can handle multiple issues simultaneously.

Common Message Switch (CMS) -- CMS is the portal member firms use to direct orders to the Exchange. CMS also provides validation of a firm's access rights, clearing information, message formats, and message terms.

Booth Automated Routing System (BARS) -- BARS is an automated order routing and management system that electronically captures and reports member firm transactions that take place on the trading floor of the Exchange, gives member firms more flexibility in order flow management, and provides a robust order inquiry capability. Member firms can direct eligible system orders, and orders larger than the electronic order size parameters, through CMS to specific booths on the trading floor. Using a touch-screen terminal, booth clerks have the option of re-directing these orders to a floor broker's wireless hand-held terminal, back through AOF for automatic routing to one of the Amex execution services, or to a local printer for manual handling by a floor broker.

Amex Order File (AOF) -- AOF is central to the Amex automated order processing systems. While performing a wide array of tasks, its main functions are to:

  • accept orders from CMS and retain order and administrative message details
  • route incoming messages and orders to the appropriate Amex execution service (NETS, AODB or Auto-Ex)
  • record and retain details of execution and route reports back to the entering firms
  • route trade reports to the market data systems for dissemination to the national market systems
  • provide order and transaction details for reports produced after-hours for member firms, brokers, and specialists

New Equity Trading System (NETS) -- NETS is an enhanced specialist display book that has accelerated the trading process and provides greater functionality and automation than ever before for updating and matching orders, quoting and reporting trades, regulating, and researching order details.

Amex Options Display Book (AODB) -- AODB is an electronic order book that has evolved into a highly automated and flexible tool for options specialists, who can customize many of its features to handle vast amounts of information on orders and executions, including national best bid/offer (NBBO), option orders by series, price and time, and competing market quotes for options traded on multiple exchanges.

Automatic Execution (Auto-Ex) -- Auto-Ex offers instantaneous automatic execution of eligible retail customer orders for options and ETFs. When the Amex quote is equal to the national best bid/offer (NBBO), it allows for automatic price improvement.


Orders may be given to a floor broker by phone, or entered through a member firm's proprietary application. In both cases, immediately upon receipt, the floor broker will "systematize" the order by entering it into the Amex Order File using the order entry feature of the Booth Automated Routing System (BARS) terminal located in the floor broker's booth on the trading floor. Once "systematized" these orders (usually large or complex orders) may be printed and physically "walked-out" to the specialist post where the specialist assembles interested buyers and sellers, or directed to a floor broker standing in a crowd through his/her wireless hand-held device. Upon execution, reports of the trade are directed back to the member firm by AOF, or by phone.