I see that for the built in T&S, IB is not really displaying the trades in the exact order of execution. For trades with the same timestamp, they sort all those trades by price, not order execution. So if a blast of selling comes in , you dont get a true picture what happened. Can't imagine why they are doing it this way.
I have an INET execution feed from another source, and the prints occur in reverse of the "expected" order. That is, if INET is offering .50 at the inside, and someone sends a buy to INET that sweeps the book up to .55, you'll see the .55 prints first and the .50 prints last. I believe they show up on the tape this way as well. I speculate that this happens because their matching engine does a two-phase process, walking from the inside, out, locking all the offers it needs to fill the buy order (so they can't be cancelled), then walking back inward, executing those locked orders and printing them.
Interesting. I was looking at the late prints in ER2 on globex. So you are saying they do the same thing? I question that only because the LAST SALE does not confirm the theory. Last sale was showing at 701.60, and t&s shows something like 703 as the last print.
I was talking about INET specifically. There could be a similar issue with GLOBEX. Also, last sale may or may not reflect the settlement price, and it may depend exactly when you look at it.
I can confirm stock777's observation for Eurex. I have reported the issue in September on the IB discussion board (including screen shot). http://www.interactivebrokers.com/discus/messages/36501/30777.html?1127725259