Orders for TAS (Trade at Settlement) products are executed at the current day’s settlement price for the standard contract or at a valid price increment above or below the settlement price of the standard contract.

To ensure appropriate and efficient messaging practices for TAS orders into CME Globex, the timing of each TAS groups’ pre-open state is randomized. The market state sequence for TAS groups has a market pause, communicated via the market data Security Status message (tag 35-MsgType=f), tag 326-SecurityTradingStatus=2 at 16:00:00 on Sunday and 16:45:00 Monday through Thursday. TAS groups then go into pre-open on Sundays between 16:00:00 and 16:01:00 Central time (CT), and Mondays through Thursdays between 16:45:00 and 16:46:00 CT.
TAS products are listed in the CME Globex Product Reference Sheet and designated TAS in the instrument name (e.g. Brent Crude Oil Last Day Financial Futures TAS).
For Cotton futures (TT), the minimum price fluctuation is .01 cents per pound. A trader may enter an order for Cotton TAS (TC) a price of 0 (which means the trader wants to trade at the TT settlement price), or at +1 or +2 (which would mean that the trader wants to trade at the TT settlement price plus one or two minimum price increments (settlement price plus .01 or plus .02), or at -1 or -2 (settlement price minus .01 or minus .02).  

TAS Calendar Spreads

See TAS Calendar Spreads (EC) for full construction and pricing details.