Margin calls are sold at a lower price to clear margins and protect from global settlement (GS).
BitUSD has just suffered GS and I believe a significant cause of this was the fact margin calls were not clearing. This is because the current formula for calculating the margin sell price considers only the feed price.
During the current downtrend feed price has been 10% above Dex price meaning the margins are being sold effectively at the Dex price.
Margin calls should be sold at "10% lower than the lesser of the feed price and Dex price."
I request the committee to immediately correct this on bitCNY to avoid another GS there.