thanks for that hint, i didn't think about the after hours. will have a check now.
thanks again. bought some shares now and was instantly filled. let's hope for the best on monday

why not? it's essentially betting with IB shareholders money.Someone tell me if I have this right...
So the total negative balance of these 5 traders should be 80% of 120m USD which is 96m USD -> ~110m EUR (at the present rate).
To go near 110m EUR underwater, n lots RF would have to go from 550m EUR to 440m EUR value.
At the time, RF margins would have been 1500 CHF per contract to control 125k EUR, with 1500 CHF equaling 1800 EUR, or around 1.4%, 70:1. For sake of argument lets assume their entire account is being used for these trades (meaning this is the best case scenario and doesn't account for the rest of their accounts being consumed).
550m EUR == 4400 lots (125k EUR each) however, they would have had atleast 1.4% in margin req already there, so it's more like 558m EUR aggregate position, or around 4465 lots total. Each contract would have required 1500 CHF/1800 EUR margin or about 8m EUR total which jives with the 558-550m EUR difference.
20% adverse move ends up with 110m EUR negative after the fact, meaning at best case (not accounting for left over money already in accounts), 8m EUR of accounts ended up producing a 110m EUR loss (14x). If you divided that equally across all 5 traders, it's around 1.6m EUR margin / account, or 888 (heh) lots each (112m EUR notional).
So imagine you're Mr. 888 with 1.6m EUR in margin being used to squeeze out 11k CHF/9.2k EUR per tick and Mr. SNB Steamroller shows up to do some construction work by paving over your entire life.
Maybe don't swing 900 lots unless you're a bank?