Does anyone know a broker that offers this? The Automatic Execution system (Auto-Ex), designed specifically for Exchange Traded Funds, provides instantaneous execution of round lot orders received via the Amex Order File (AOF). This includes orders entered from off of the trading floor via CMS as well as those entered from on the Amex trading floor through the Booth Automated Routing System (BARS). Download the ETF Auto-Ex List Questions pertaining to ETF Auto-Ex should be directed to Robert Malvino at (212) 306-1606 or the Amex Service Desk at (212) 306-1763. Similar to NX?