Stock Selection using Recon *George H. John !Peter Miller Randy Kerber Comp. Sci. Dept Lockheed AI Center 1422 Flora Ave. Stanford Univ. 3251 Hanover Street San Jose, CA 95130 Stanford, CA 94305 Palo Alto, CA 94304 gjohn@cs.stanford.edu pmiller@aic.lockheed.com kerber@best.com * http://robotics.stanford.edu/~gjohn/ ! http://hitchhiker.space.lockheed.com/~recon/ We approach the problem of stock selection from the perspective of knowledge discovery in databases: given a database of several years of quarterly information on over a thousand companies, discover patterns in the data that will allow one to predict which stocks are likely to have exceptional returns in the future. The database includes measures of trends in the stocks' prices as well as fundamental data on the companies. For this task we employed the Recon system, which is able to induce a set of classification rules or a neural network to model the data it is given. To evaluate Recon's performance in the stock selection task, we paper-traded a portfolio of the fifty stocks ranked highest by Recon. When trading costs were taken into account, Recon's portfolio had a total return of 238% over a four-year period, significantly outperforming the benchmark, which returned 93.5% over the same period. The performance is not attributable to growth/value or size effects alone. We conclude that Recon is a valuable tool for stock selection. Recon is a trademark and service mark of Lockheed Missiles & Space Company, Inc., subsidiary of Lockheed Corporation, a Lockheed Martin Company. Citation: George H. John, Peter Miller, and Randy Kerber. Stock Selection using Recon. In Y. Abu-Mostafa, J. Moody, P. Refenes, and A. Weigend, editors, _Neural Networks in Financial Engineering_, pages 303--316. World Scientific, London, 1996.