Investor Corner/Building and judging a portfolio/Performance Measurement
3.2.3 Rolling Returns
Rolling returns calculate performance over many overlapping periods, such as every possible three-year window in a fund's history, rather than a single fixed start and end date. This shows consistency far better than one point-in-time figure.
Why a single-period return can mislead
A fund's quoted 5-year return depends entirely on which specific starting date happens to be chosen. A fund that looks excellent measured from one particular date might look mediocre measured from a date just a few months earlier or later, purely because of when the measurement window happened to start and end, not because anything about the fund actually changed.
Rolling returns measure a fund's performance over every overlapping period of a given length within its history. Instead of looking at a single 5-year return (say, 2019 to 2024), rolling 5-year returns show the return for every possible 5-year window: 2010-2015, 2010.01-2015.01, 2010.02-2015.02, and so on. This produces a distribution of outcomes rather than a single number, giving a much richer picture of how the fund has behaved across different market conditions.
How rolling returns fix this
Instead of one fixed window, rolling returns calculate the same period length, say three years, starting from every possible date across a fund's full history, then look at the entire resulting distribution. A fund that consistently delivered solid three-year rolling returns across nearly every window looked at is a genuinely different, more reassuring picture than one that only looks good from one specific, cherry-picked starting date.
The power of rolling returns is that they reveal consistency. A fund with a high average 5-year CAGR but a wide dispersion in rolling returns (sometimes 25%, sometimes -5%) is a very different proposition from one with a slightly lower average but narrow dispersion (consistently 10-16%). The first fund may have a better headline number, but the second is more predictable and easier to rely on for goal-based planning. The rolling return distribution also shows the worst-case outcome over that holding period, which is far more useful for risk assessment than the average or the most recent return.
How to use rolling returns when evaluating a fund
Look at the proportion of rolling windows in which a fund beat its benchmark or category average, not just its most recently quoted single-period figure. A fund that has beaten its benchmark in most rolling windows across a full market cycle has demonstrated a more genuinely consistent edge than one that simply happens to look good right now.
How PriLytics helps. PriLytics tracks your portfolio's value against your benchmark continuously over time, letting you see performance across whatever period you choose rather than a single fixed window. Compare against a benchmark.
In India, 10-year rolling return analysis of the Nifty 50 shows that there has been no 10-year period with a negative return, and the vast majority of 10-year periods have delivered 10-15% CAGR. For the Nifty Smallcap 250, the dispersion is wider: some 10-year windows have delivered 20%+ while others have delivered single digits. This is the most concrete way to visualise the equity holding period argument: the longer you hold, the narrower the range of likely outcomes, and the more predictable the result. Rolling returns make this visible in a way that a single return figure cannot.