A Valuation Study of Stock-Market Seasonality and Firm Size

Abstract

Existing studies on market seasonality and the size effect are largely based on realized returns. This paper investigates seasonal variations and size-related differences in cross-stock valuation distribution. We use three stock valuation measures, two derived from structural models and one from book/market ratio. With each measure, we find that the average level is the highest in midsummer and the lowest in mid-December. Furthermore, the valuation dispersion (or, kurtosis)across stocks increases towards the year end and reverses direction after the turn of the year, suggesting increased movements in both the under-and-overvaluation directions. Among size groups, small-cap stocks exhibit the sharpest decline in valuation from June to December and the highest rise from December to January. For most months, small-cap stocks have the lowest valuation among all size groups. In a typical month, small-cap stocks show the widest cross-stock valuation dispersion, meaning they are also the hardest to value. Overall, large stocks enjoy the highest level of valuation uniformity and are the least subject to seasonal valuation variations.