标题： F&O到期日与首日SIPs：对印度Nifty 50时间段优势的22年分析 显示英文标题

标题： F&O Expiry vs. First-Day SIPs: A 22-Year Analysis of Timing Advantages in India's Nifty 50

摘要： 这项研究对印度Nifty 50指数在22年期间（2003--2024）的定期投资计划（SIP）表现进行了比较分析，重点研究了投资时间——特别是每个月的第一个交易日（FTD）与期货和期权（EXP）的每月到期日。该研究通过数学验证表明，SIP收益与投资金额无关。利用历史指数数据，研究发现，在短期到中期时间范围内（1--3年），在期货和期权到期日进行的SIP每年的表现比第一个交易日SIP高出0.5--2.5%，这凸显了由于到期相关市场波动带来的战术优势。然而，这种优势在更长的时间段（10--20年）内会减弱，再次确认持续的长期投资是财富积累的关键驱动因素。此外，该分析通过揭示Nifty 50指数SIP的20年复合年增长率（CAGR）约为6.7%（税前），明显低于广泛宣传的12--15%回报率，从而挑战了行业普遍观点。这项研究为零售投资者和财务规划者提供了关于印度股市SIP策略中投资时机作用的新见解。 显示英文摘要

摘要： This study presents a comparative analysis of Systematic Investment Plan (SIP) performance in India's Nifty 50 index over a 22-year period (2003--2024), focusing on the timing of investments -- specifically, the first trading day (FTD) of each month versus the monthly expiry day of Futures and Options (EXP). The research establishes, through mathematical validation, that SIP returns are independent of the invested amount. Leveraging historical index data, the study finds that SIPs timed on F\&O expiry days consistently outperform FTD-SIPs by 0.5--2.5\% annually over short- to medium-term horizons (1--3 years), highlighting a tactical advantage due to expiry-related market volatility. However, this advantage diminishes over longer durations (10--20 years), reaffirming that sustained, long-term investing is the key driver of wealth accumulation. Additionally, the analysis challenges prevailing industry narratives by revealing that the 20-year compounded annual growth rate (CAGR) of Nifty 50 SIPs stands at approximately 6.7\% (pre-tax), significantly lower than the widely advertised 12--15\% returns. This research offers novel insights for retail investors and financial planners on the role of investment timing in SIP strategies within the Indian Indian equity market.