The purpose of this paper is to investigate the effect of the "limits of arbitrage" on securities mispricing. Specifically, I investigate the effect of the availability of substitutes and financial constraints on stock mispricing. In addition, this study investigates the difference in the limits of arbitrage, in the sense that it will lead to lower mispricing for these stocks, relative to non-S&P 500 stocks. I also examine if the lower mispricing can be attributed to their lower limits of arbitrage. Modern finance theory and efficient market hypothesis suggest that security prices, at equilibrium, should reflect their fundamental value. If the market price deviates from the intrinsic value, then a risk-free profit opportunity has emerged and arbitrageurs will eliminate mispricing and equilibrium is restored. This arbitrage process is characterized by large number of arbitrageurs which have infinite access to capital. However, a better description of reality is that there are few numbers of arbitrageurs to the extent that they are highly specialized; and they have limited access to capital. Under these condition arbitrage is no more a risk-free activity and can be limited by several factors such as arbitrage risk and transaction costs. Other factors that are discussed in the literature …