Article’s

Abstract – Systematic Investment Plans (SIPs) are marketed widely to Indian retail investors as a disciplined, risk-reducing alternative to lump-sum investment through periodic fixed-amount purchases, commonly termed rupee-cost averaging. This paper presents a holistic empirical test of that claim using Nifty 50 index data from January 2010 to June 2022. Beyond a single-window comparison, the analysis constructs 91 overlapping five-year and 31 overlapping ten-year rolling windows across the full sample to assess how consistently lump-sum investing outperforms SIP across different starting points; computes annualised volatility, maximum drawdown, and Sharpe ratios for both strategies; stress-tests outcomes using a crash-timed worst-case start date; and decomposes results across two five-year sub-periods. Across the primary January 2012–June 2022 window, lump-sum investing produced a terminal value of ₹49.3 lakh against ₹25.0 lakh for an equivalent-capital SIP, and lump sum outperformed SIP in 97.8% of five-year and 100% of ten-year rolling windows tested. Despite this consistent terminal-value advantage, SIP’s money-weighted annualised return (XIRR) exceeded lump sum’s CAGR in the median rolling window, a result reconciled by the differing amounts of time capital is at risk under each strategy. We discuss why SIP nonetheless retains behavioural and cash-flow-management value for the large share of retail investors who do not have a lump sum available at the outset, and outline the market conditions under which SIP’s relative performance would improve. Key Words: systematic investment plan, rupee-cost averaging, dollar-cost averaging, lump-sum investing, Nifty 50, retail investing, emerging markets, behavioural finance, rolling-window analysis.