What is the general consensus on trading with yourself, filling your own orders either by mistake or during price spikes. Is this illegal, will you get fined by the exchange if this happens? I ask because there is very slim chance that one of my resting stop orders could slip and fill another resting limit order at a lower price (around 15 ticks lower). The exchange i am trading on (eurex) only supports stop orders, does not support stop limit orders, otherwise i could specify a limit on the stop to prevent the orders from crossing.
I don't know about Europe, but IIRC - it is illegal in the US. IIRC, it has something to do with market manipulation or gaming the markets. If it were US, then I would say check the law (it is on-line) and check the rulebook for the exchange. Depending upon which country in Europe, thy may have the law on-line as well and the rulebook for the exchange may be on-line as well. -gastropod
Doubt there is a law about that in germany, but its against Eurex rules. Google the Eurex-website for "Cross & Pre-arranged Trades" to find more info.
If it's by accident then I wouldn't worry too much. If you do it on purpose then you may get in trouble.