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Characteristics of pricing errors in stocks implied by autocovariance and ‘drag’

In this article, we estimate the lower bounds on the volatility and autocorrelation of pricing errors in stocks and infer the market-wide component in the pricing errors, by combining information from the autocovariance and ‘drag’ in stock returns. For the smaller US stocks, we estimate lower bounds of 8−10% for the volatility and 0.3−0.5 for the autocorrelation of the pricing errors, at monthly horizon. We infer that approximately 50% of the pricing errors of the smaller stocks originate from the market-wide component, whereas for larger stocks, virtually all of the pricing errors are market-wide. In practice, this evidence means that market-wide bubbles and busts are far more important than idiosyncratic sources of pricing errors, like thin trading, low liquidity or little analyst following.