IB's data feed:
Eurex distributes two data feeds: the member data feed and the data vendor data feed.
IB distributes the member data feed to its customers, but not tick per tick, only as 0.7 second snapshot.
The data vendors distribute the other data feed to their customers. It is a 2-second consolidated data feed.
So there will be a lot of trades at prices which will not be shown in IB's TWS (nor in any chart program depending on this data feed). I have seen 11 tick drops in the FGBL which did not show up in the TWS.
Neither will all trades esp. at temporary high/lows be shown in the data vendor data feed. It is a common complaint among traders that their stops have been triggered at prices which they did not see in their charts (nor in the TWS).
It is a fact you have to be aware of. It will happen primarily in fast moves and more often in volatile instruments like the FDAX.
As to the stop orders:
You either use a native Eurex stop order (shown green in the TWS), which is turned into a market order, when the market trades at your trigger price or you use a stop limit order, which is simulated by IB (shown dark blue in the TWS). This order will be sent to the Eurex as limit order, when the market triggers it (default method is last trade).
Both methods have advantages and disadvantages: Today, during the outage of Eurex trading at IB the native stop order had a clear advantage.
Regards
Bernd Kuerbs