For the guys who do native exchange traded spreads are the commissions usually double to account for both legs? Is it treated as a real separate instrument by the exchange where each leg cannot be managed individually or is it really just an exchange provided instrument to remove legging risk and that's about it?
1. The commission is not "round turn"; just for the individual buy and sell component contracts executed in the exchange spread combination.
2. You can leg out of an exchange spread provided that the instruments being closed out are identical. You can also execute calendar spreads and roll individual legs.
3. The advantage to exchange spreads is execution and slippage risk ( legging ). You don't need to leg or use automation for trading them. Another advantage is that exchange supported spreads appear in the order book, or ticket, or DOM window, as an individual price ( the collective spread differential ). In other words, for that Liffe Euribor spread I have above, the market would be -75 bid and -74 offered. Once executed, my fill window will have all three spread legs listed by quantity and price - and those exact quantities and prices will appear on your daily statement. Furthermore, that singular exchange supported spread will accommodate all of the types of orders that singular flat price futures ( like ESM5 for example ) use. So, for that Euribor butterfly exchange spread, I can use FOK, OCO, MOO, MOC, limit, stop limit, etc. etc.
4. Depending upon your execution platform and FCM, you will have to ask the firm's Risk Manager to enable your platform settings to receive exchange supported spreads. There are, literally, hundreds if not thousands of them depending upon the exchange product portfolio.