has anybody run into this kind of problem market price on the blotter or in account window is showing the closing regular session price not the current premarket or afterhour market price. if a stock is down in the afterhr session and you go short eg three pts down from the close you will show in the account window immediately a loss of $300/ 100share because the calculation is assuming that the position will be liquidated at the regular market closing price. in the premarket and aftermarket session profit/loss are being calculated off the regular hr. closing price not the current market place. in the account window .there are likely to be margin issues if positions are large enough anybody ever have to deal with this problem.