Structural Decoupling of the Indian Equity Market: Empirical Evidence on the Shifting Dominance from Foreign to Domestic Institutional Investors

Abstract

The Indian equity market has undergone a profound structural transformation, gradually transitioning from a state of heavy reliance on Foreign Institutional Investor (FII) activity to a domestically anchored ecosystem. This study empirically investigates the "Structural Decoupling" hypothesis by examining the relationship between net FII flows, Domestic Institutional Investor (DII) flows, and the performance of benchmark indices the Nifty 50 and BSE Sensex over a 60-month period from January 2021 to March 2026. Employing a descriptive and analytical research design, the study utilizes secondary data sourced from the National Securities Depository Limited (NSDL), the Securities and Exchange Board of India (SEBI), and the National Stock Exchange (NSE). Statistical tools including Pearson's Correlation and Linear Regression are applied to a sample of N = 60 monthly observations. The findings reveal a statistically insignificant relationship between FII flows and benchmark indices (r = -0.140 for Nifty 50; p = 0.286), while DII flows demonstrate a robust and significant positive correlation (r = 0.685 with Nifty 50; p < 0.001). Regression analysis further confirms that DII flows alone account for approximately 46.9% of the variation in the Nifty 50 (R² = 0.469). A strong inverse relationship between FII and DII flows (r = -0.674; p < 0.001) validates the existence of an "Absorption Effect," wherein domestic institutions systematically counterbalance foreign capital exits. These results provide compelling empirical evidence that the Indian market has materially evolved from an FII-dependent to an FII-integrated, domestically anchored system, with significant implications for retail investors, portfolio managers, and financial policymakers.