The Complexity of the Stock Market

Abstract

The stock market is a complex system, somewhere between the domains of order and randomness. Ordered systems are simple and predictable, and random systems are inherently unpredictable. Simple theories do not adequately describe security pricing, nor is pricing random. Rather, the market is permeated by a web of interrelated return effects. Substantial computational power is needed to disentangle, model, and exploit these return regularities.

Keywords: market complexity, return regularities, anomalies, disentangling, pure returns, naïve returns, ordered systems, complex systems, random systems, size effects, P/E, B/P, earnings trends, return reversals, calendar effects, efficient market, CAPM, dividend discount model, multivariate regression

JEL Classification: G14