An electronic trading system utilizes a Match Engine that receives orders, stores them internally, calculates tradable combinations and advertises the availability of real and implied orders in the form of market data. The tradable combinations may include spread orders where one leg of the spread has a different tick size than the other or where the tick of the spread contract is different from the tick size in one or both legs. A method and system for calculating on-tick leg prices in an equitable and predictable manner is provided.