PickStock (copyright 2003, Bell Software and Services, Inc.) uses principal components analysis to search out potentially underpriced stocks by analyzing a user-supplied database of historical stock prices. The program is believed to be an implementation of what is known in the financial market modeling community as 'arbitrage pricing theory' (see for example S. Ross, 'The arbitrage theory of capital asset pricing', J. Economic Theory, vol. 13, pp. 341-360, 1976). The theory postulates that a given vector of prices (for example, today's price for a set of stocks) can be explained by a linear combination of underlying economic components. While there is apparently substantial debate in the economic community as to the viability of the arbitrage pricing theory, this application provides a tool to test it out on real data. |