A system and method for regulating order entry based on an acceptable slop range for a trading strategy are described. According to one example embodiment, a trader may define an acceptable slop range for a trading strategy as a percentage. The trader may also define a variable to associate with the trading strategy. Using a spread trading algorithm, a spread price axis is generated and the trader may place an order for the trading strategy at a desired price, comprising placing an order in one leg market dependent on the market conditions of another leg market. Using the acceptable slop range, the system keep the net cost to the trader within the acceptable slop range, by regulating orders in the leg markets. Defining an acceptable slop range as a percentage allows the trader to monitor and regulate their profits and loss, regardless of the type of spread trading algorithm used or the placement of an order o the spread price axis.