The invention relates to a tool for estimating a pre-trade implementation shortfall for financial instruments. Through evaluating a number of factors, including the size of the order, the average daily volume of the stock, the average bid-ask spread of the stock, the volatility of the stock and the exchange on which the stock trades, the present invention estimates the cost of a trade. Using the disclosed system and method, a trader or fund manager may determine when and how to implement trades of varying size.