"What Goes Up Must Come Down"-How Charts Influence Decisions to Buy and Sell Stocks

Abstract

Five experiments examine how charts depicting past stock prices influence investing decisions. We expected investors to use extreme past prices depicted in charts as comparison standards to which expectations about future prices are assimilated. Investors should thus expect stocks depicted in a chart with a salient high to perform better than stocks depicted in a chart with a salient low. And as a consequence, investors should be more likely to buy and less likely to sell stocks depicted in a chart with a salient high than a low. Results of five experiments support this reasoning. Whether investors are private or professional and whether background information about the stock was limited or abundant, expectations about future prices assimilated to extreme past prices. Consequently, investors buy more and sell less when the critical chart is characterized by a salient high than a low. The implications of these findings for the core role comparison processes play in investing decisions are discussed.