Size Effect in Indian Equity Market: Myth or Reality?

Abstract

This study revisits size effect and its associated issues, in the Indian market, as recent studies question the persistence of size premium in the global context. We use data from NIFTY 200 stocks for the period 2005 to 2018 and find size effect to be significant for both market-based and accounting-based measures of size. It is not impacted by any definitional issues as highlighted by Berk (Financ Anal J 53(5):12–18, 1997). Size effect also remains significant despite alternative portfolio constructions i.e. forming quintiles, deciles, scores of portfolios even though the premiums vary. Existing literature on size anomaly does not focus on size drift and survivorship bias. We specifically address these dimensions relating to size effect which have received less attention in prior work. In this study, size effect is found to be sensitive to drift in market capitalization. Historical market capitalization used to categorize medium (large) firms may now be a basis for classifying small (medium) firms in recent time periods. Small sized portfolio adjusted for drift provides substantially higher return compared to unadjusted small sized portfolio. Further, to evaluate survivorship bias, size-based portfolios are redesigned using changing components of NIFTY 200 for each formation period. This leads to considerable weakening of size effect. Investors must take this fact into consideration while creating size based portfolios. However, upon using another stable universe of F&O traded stocks, size effect is found to be significant. The study contributes to size anomaly literature for Indian market and shall be useful for portfolio managers, investors, academia and regulators.