A comprehensive 30-year analysis by WhiteOak Capital Mutual Fund has examined the impact of monthly SIP timing on investment returns. The study, covering the period from August 1996 to July 2026, analyzed SIP investments made on the best, worst, and 15th day of every month using the BSE Sensex TRI (Total Return Index). According to the analysis, returns were measured using XIRR (Extended Internal Rate of Return), which calculates annualised returns while accounting for the timing of each monthly investment. The BSE Sensex TRI captures both price changes and dividends, assuming dividends are reinvested.
The study revealed that monthly SIPs in the BSE Sensex TRI generated an annualised return of 13.75% when investments were made on the best day of each month. Investing on the worst day of each month delivered 13.27% returns, while investing on the 15th of every month gave 13.53% returns. As reported by Mint, the best day represents when the Sensex recorded its highest performance in a month, while the worst day marks the weakest performance. For a ₹1,000 monthly SIP starting in August 1996 and continuing until July 2026, the total investment would have been ₹3.6 lakh.
The study demonstrates the minimal impact of timing on long-term wealth creation. Based on the given XIRRs, the approximate final values by July 2026 would be ₹43.3 lakh for the luckiest investor (best day every month), ₹39.3 lakh for the most unlucky investor (worst day every month), and ₹41.4 lakh for the disciplined investor (15th of every month). According to the analysis, the difference in final wealth between the luckiest and unluckiest investors would be around ₹4 lakh, even though both invest the same amount every month for 30 years. The gap between best and worst outcomes was just 0.48 percentage points over nearly 30 years.
Recent market data reveals a concerning trend in SIP participation patterns. While monthly SIP inflows in India have crossed record highs repeatedly in recent months, driven largely by higher-ticket investors increasing their contributions, millions of small investors running SIPs under ₹500 per month are quietly discontinuing their investments. According to GoCredit's analysis, cancellation rates among micro-SIP accounts are disproportionately high during market corrections, creating what analysts describe as a two-speed market where large and affluent investors are deepening their commitment while first-time, low-income investors are exiting the mutual fund habit entirely. The data shows that accounts investing between ₹500 and ₹1,000 have fallen by nearly 14 lakh over the past financial year, marking the first decline in years for this segment.
