Comparing the Returns of Holding Stocks in the Dow Jones Index Constant vs. Investing in the Actively Updated Dow Index

Abstract : This study compares the performance of a frozen Static portfolio of Dow Jones Industrial Average (DJIA) constituents with the actively rebalanced Dynamic Dow across three decades: 1990–1999, 2000–2009, and 2010–2019. The objective is to evaluate whether a passive buy-and-hold strategy can match or exceed the returns of the updated index, and to analyze differences in risk, volatility, drawdowns, and sectoral shifts. Performance was assessed using compound annual growth rate (CAGR), volatility, Sharpe ratios, maximum drawdowns, and maximum runups, supplemented by t-tests and regressions for statistical significance. Results show that while average returns were not statistically different, the Dynamic Dow consistently achieved higher Sharpe ratios and lower volatility. It materially reduced losses during the downturn of 2000–2009 and captured stronger runups in bull markets, reflecting the benefits of constituent replacement. Overall, findings suggest that index reconstitution enhances efficiency, reduces downside risk, and better aligns portfolios with structural economic change.