Support Board

In the case of a long position, when a sell market order is submitted and the quantity of all sell working orders (which includes this market order) is less than the current position quantity, then this is allowed to pass the margin check because this is reducing risk. There still is a recalculation of the required margin in this case. Although if the account is under margin, the order is allowed to go through since this reduces risk.

In the case of a short position, when a buy market order is submitted and the quantity of all buy working orders (which includes this market order) is less than the current position quantity (interpreted as an absolute value), then this is allowed to pass the margin check because this is reducing risk. There still is a recalculation of the required margin in this case. Although if the account is under margin, the order is allowed to go through since this reduces risk.