Abstract: An electronic exchange system network includes a trader site having an automated trading system capable of submitting orders to an exchange site. The automated trading system determines whether an order should be submitted based on, for example, the current market price of an option and theoretical buy and sell prices. The theoretical buy and sell prices are derived from, among other things, the current market price of the security underlying the option. A look-up table stores a range of theoretical buy and sell prices for a given range of current market price of the underlying security. Accordingly, as the price of the underlying security changes, a new theoretical price may be indexed in the look-up table, thereby avoiding calculations that would otherwise slow automated trading decisions. Other techniques may be used in addition or in the alternative to speed automatic decision-making. In addition, a system of checks may be conducted to ensure accurate and safe automated trading.