CM........if you're talking about an automated stop loss such as that offered by AOT then they require you to place a limit on your sell price.
Eg) Your order may read "If AMP falls to 4.70 or below sell x number of shares at a limit of (you specify)".........say 4.50. If it then went into a halt and gapped down to open at 4.49 and then died a rapid death you wouldn't get filled as your order would be sitting in the market at 4.50
