Hi vinsom, boatman, (& jcl?),
My initial reaction was the same as boatman's - it's the "disaster stop" - i.e., the stop sent to the broker, not the script's real stop (hidden from the broker to prevent stop hunting).
However, elsewhere jcl has noted 30% as the general figure for these stops (tighter for certain assets/brokers), and this stop is quite a bit beyond that - so, wondering if something else is going on here?