Peter automatically places a pending order at $11 (slightly above market price), expecting to buy back an apple as soon as possible to make up the shortfall. Soon Peter buys back the apple for $11, leaving Peter with $101 and 10 apples in stock, or +$1 and 0 apples. Although it cost $1 more, the extra $2 received through the slippage was enough to make up for it, and Peter helped his boss make a net profit of $1.