What is standard deviation?
Standard deviation is the classic measure of volatility - how far a fund’s returns typically stray from their own average, in either direction. It doesn’t distinguish good swings from bad ones; that’s what downside deviation (used in the Sortino Ratio) is for.
σ = √( Σ(Ri − R̄)² / N )
Lower means a smoother path to the same destination - not automatically a “better” fund, just a steadier one.
Real comparison across 6 funds
CHART
3Y Annualized Std Deviation - 6 real funds
All 6 funds sit in a fairly tight 9.7%-12.5% band - none of these are extreme outliers on volatility alone.
Funds compared: Parag Parikh Flexi Cap · DSP Value · ICICI Prudential Value · SBI Focused · Parag Parikh ELSS Tax Saver · SBI Multicap
Reading the spread
Across these 6 funds, 3-year standard deviation runs from 9.74% (Parag Parikh Flexi Cap) to 12.51% (SBI Multicap), a gap of 2.77%. The middle value is 10.82%, with 3 of 6 above it. Taking lower as better, Parag Parikh Flexi Cap leads and SBI Multicap trails on this measure alone.
How to use it in practice
Read standard deviation as the typical size of a fund’s swings around its average return. A fund with a higher figure has more variable returns, so it needs a longer holding period and a stronger stomach. Use it to match a fund to your own tolerance: if a 15% swing would make you sell, avoid a fund whose volatility regularly produces one. It is also the denominator in Sharpe, so it links directly to risk-adjusted return.
Common mistakes
Standard deviation counts upward and downward moves the same way, so a fund that rose steeply looks risky even though investors were happy. It also assumes returns are spread symmetrically, which real markets are not: crashes are sharper than rallies. For the damage side of risk, check maximum drawdown and Sortino next to it.
Frequently asked questions
What does a high standard deviation mean for a mutual fund?
It means the fund’s returns have varied widely around their average, so it has been more volatile. That is neither good nor bad in itself, since higher risk can come with higher return, but it tells you how bumpy the ride has been and how long you may need to stay invested.
How is annualised standard deviation calculated?
Periodic returns, usually daily or monthly, are measured for their spread around the mean, and the result is scaled up to a yearly figure. The exact window matters, so Punji shows a trailing 3-year figure for comparability.
Is standard deviation the same as risk?
It is one measure of risk, the variability of returns. It does not capture permanent loss, concentration or credit risk, so it should be read with maximum drawdown and the fund’s own risk label.
WHAT THIS MEANS FOR YOU Standard deviation alone doesn’t tell you if the ride was worth it - always pair it with a return figure (like Sharpe Ratio) rather than judging volatility in isolation.
METHODOLOGY Annualized standard deviation of daily returns over a trailing 3-year window as of 2026-08-31. Data: Punji risk analytics. Not investment advice.