Evaluating the Strategy of Annual Index Rebalancing in SIPs

Investor Attention Grabbers: The Case for Staying Invested

Every year, one market segment tends to capture investor attention, with many Systematic Investment Plan (SIP) investors tempted to ask a simple question: why stay invested in one category when you can simply shift to the one that performed best last year?

The idea of moving towards strength, avoiding underperformers, and potentially earning better returns sounds logical on paper. However, a recent report by WhiteOak Capital suggests that this strategy may not be as straightforward as many investors expect.

The "Follow the Winner" Strategy

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WhiteOak Capital analyzed two case studies comparing annual SIP switching strategies across large-cap, mid-cap, and small-cap indices with staying invested in a single index. The strategy involved shifting every year to the last year's winner among the three market segments.

In simple terms, if small-caps were the top performers one year, the SIP would shift there the next year. If large-caps topped returns next year, the SIP would shift again. This approach aims to stay invested in the market's strongest-performing segment instead of sticking to just one category for years.

Case Study 1: Midcap SIP

The first case study followed an investor who started a SIP in the Mid Cap Index in FY2006 but did not stay put. Instead, the SIP kept moving every year to whichever category delivered the best returns in the previous year. Over the period ending April 30, 2026, this "follow the winner" approach generated an XIRR of 14.76 percent.

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In contrast, a second investor who simply stayed invested in the Mid Cap Index throughout the same period without making any switches ended up with a higher XIRR of 16.96 percent. The gap was visible in rolling returns as well, with the average 10-year rolling SIP return for the switching strategy standing at 15.73 percent, compared with 17.54 percent for staying invested in the midcap index.

Case Study 2: Smallcap SIP

The second case study tested the same strategy with an investor starting SIPs in the Small Cap Index. Like the earlier example, the SIP did not stay in one place. Every year, the investment shifted to whichever category had emerged as the top performer in the previous year. As of April 30, 2026, the investor who kept switching generated an XIRR of 14.75 percent.

Meanwhile, an investor who simply stayed invested in the small cap index throughout the period earned a slightly higher XIRR of 14.89 percent. The gap here was narrower than in the midcap example, but rolling returns still showed that frequent switching did not create a meaningful advantage.

Why Chasing Recent Winners Can Get Tricky

One pattern that stood out across both case studies is that the market's top-performing segment kept changing over time. Industry experts point out that a category that led returns in one phase was not always the leader in the next. As a result, the SIP strategy involved frequent shifts between large-cap, mid-cap, and small-cap indices depending on which segment had performed best in the previous year.

The findings highlight how long-term SIP outcomes can vary significantly from short-term market leadership trends, especially when market cycles keep shifting across segments. The data does not suggest that large-cap, mid-cap, or small-cap investing is inherently better or worse. Different categories outperform at different phases of the market cycle.

Takeaway

The report's findings suggest that moving SIPs every year to chase the previous year's top-performing category does not consistently deliver stronger long-term outcomes. Instead, staying disciplined with allocations and continuing SIPs through market cycles may prove more effective than making frequent tactical shifts based on short-term performance trends.