Investor Behaviour

Why Two Investors Earn Different Returns from the Same Mutual FundBy FundSageAI · June 18, 2026 · 10 min read

Same fund. Same five-year period. One investor earns 9.2% XIRR. The other earns 15.8%. The fund did not change. What changed was how each investor behaved — when they paused, when they added, when they switched.

If you have ever compared your mutual fund returns with a friend who invested in the same fund and found a significant difference, you are not imagining it. The difference is real, measurable, and has a name: the behaviour gap. It is the gap between what a fund earns and what an investor in that fund actually earns — created entirely by the investor's own decisions.

This article explains exactly how the gap opens, which decisions create the most damage, and how to close it permanently.

Key Takeaways

Two investors in the same fund over the same period can have XIRR differences of 5-10% annually — the fund did not cause this, their behaviour did
The behaviour gap — fund CAGR minus investor XIRR — averages 3-4% annually according to DALBAR's multi-decade study
Stopping SIPs during corrections is the single most costly decision; it eliminates cheap unit accumulation at the exact moment it matters most
Your XIRR is what you actually earned. CAGR is what the fund earned. They are almost never the same
The solution to the behaviour gap is structural, not psychological — automate investments and set written rules for when you will and will not act

In This Article

1The Same Fund, Two Completely Different Outcomes
2What XIRR Actually Measures (And Why It Is Not CAGR)
3The Behaviour Gap: DALBAR Data and Why It Applies to Indian Investors
4The 5 Decisions That Create the Gap
5The March 2020 Experiment: Two Identical Portfolios Diverge
6Why We Make Emotional Decisions With Money
7The Discipline Premium: What Consistent Investors Actually Earn
8How to Quantify Your Own Behaviour Gap
9Making Discipline Structural: 5 Rules That Work
10How FundSageAI Shows You Your Behaviour Gap

1The Same Fund, Two Completely Different Outcomes

Investor A (Disciplined)

15.8%

XIRR over 5 years

Continued SIPs through all corrections. Added lumpsum in March 2020.

Investor B (Reactive)

9.2%

XIRR over 5 years

Paused SIPs during 2020 crash. Restarted in Oct 2020 after recovery.

Both investors were in the same Nifty 50 index fund. Both started SIPs of ₹10,000/month in January 2019. Both held through December 2023. The fund itself delivered 14.3% CAGR over that period. Yet Investor A earned 15.8% XIRR and Investor B earned 9.2%.

The difference: Investor B paused SIPs from March to September 2020 (the COVID crash and initial recovery) and restarted in October 2020 when the Nifty had already recovered to 12,000 from its March low of 7,610. Investor A missed nothing — accumulating cheap units at 7,600-9,000 NAV levels that then tripled in value by 2023.

2What XIRR Actually Measures (And Why It Is Not CAGR)

CAGR — Compound Annual Growth Rate — measures what a fund delivered from a fixed start point to a fixed end point. It is the fund's story. XIRR measures what you personally earned, accounting for the exact date and amount of every cash flow in and out. It is your story.

For a lump-sum investor who invested once and held, CAGR and XIRR are almost identical. For an SIP investor — which is most Indian mutual fund investors — they can be very different. If you invested more during high-NAV periods (market peaks) and less during low-NAV periods (because you paused during corrections), your XIRR will be lower than the fund's CAGR. If you invested consistently and added during corrections, your XIRR can exceed the fund's CAGR.

The only honest return metric for SIP investors is XIRR. Any app that shows you a trailing 1-year or 3-year CAGR is showing you the fund's return, not yours. They can differ by 5-8% annually for active SIP investors over typical 5-7 year periods.

3The Behaviour Gap: DALBAR Data and Why It Applies to Indian Investors

DALBAR Inc., a US financial research firm, has published its Quantitative Analysis of Investor Behaviour (QAIB) annually since 1994. The 2024 report shows that over a 20-year period, the average US equity fund investor earned approximately 7.0% annually while the S&P 500 delivered approximately 9.8% annually. The behaviour gap: 2.8% per year, for two decades, compounding into a massive wealth difference.

India-specific data is less robust, but available evidence suggests the gap is comparable or wider. The Nifty 50 has delivered approximately 13-14% CAGR over the last 20 years. AMFI data on average SIP holding period (under 3 years for a majority of accounts) and frequent SIP pause and restart patterns during market corrections suggest the average retail investor's XIRR is significantly below the index's CAGR.

Why the behaviour gap may be wider in India

Higher market volatility — Indian equity markets have historically shown larger swings than US markets, triggering more frequent behavioural reactions
Shorter investment horizons — median SIP account age is under 3 years; most investors do not hold through a full market cycle
Distributor-driven switching — regular plan investors are sometimes encouraged to switch funds by distributors earning new commissions
Low financial literacy on XIRR — most investors monitor NAV returns rather than personal XIRR, hiding the impact of poor timing decisions

4The 5 Decisions That Create the Gap

The behaviour gap does not come from a single catastrophic decision. It comes from a pattern of small, individually-justified decisions that compound into a large XIRR drag.

Stopping SIPs during corrections

Impact: Very High

Eliminates the cheap unit accumulation that is the entire mathematical advantage of SIP investing. The worst months to stop — the correction months — are exactly when continued investing creates the most value.

Redeeming and re-investing

Impact: High

Each redemption triggers LTCG or STCG tax. Re-investment resets the cost basis at the higher current NAV. Round-trips on equity funds can cost 15-20% of the exit value in tax and re-entry cost.

Starting SIPs later than planned

Impact: High

One additional year of compounding at age 25 vs age 26 is worth more than 5 additional years of SIPs at age 45. Delay is the most expensive inaction.

Lumpsum investments at market peaks

Impact: Medium

Investors tend to add lumpsum when confidence is highest — which is when markets have already run up significantly. Concentrating additional investment at high NAVs dilutes the rupee cost averaging advantage.

Switching funds every 1-2 years

Impact: Medium

Each switch resets the holding period for LTCG purposes, creates a tax event, and loses the low-NAV units accumulated in the previous fund. Short holding periods mean you never benefit from compounding in any single fund.

5The March 2020 Experiment: Two Identical Portfolios Diverge

March 2020 was the most significant behavioural test for Indian equity investors in recent history. The Nifty 50 fell from 12,350 in January to 7,610 in late March — a 38% decline in under 8 weeks. AMFI data shows SIP registrations fell sharply and SIP pauses spiked. Millions of investors stopped their SIPs during exactly the period that would have generated the highest future returns.

Period	Nifty level	Investor A (continued)	Investor B (paused)
Mar 2020	7,610	₹10,000 SIP — max units at low NAV	Paused — 0 units bought
Apr 2020	9,860	₹10,000 SIP — still cheap units	Paused — 0 units bought
Jun 2020	10,300	₹10,000 SIP	Paused — 0 units bought
Oct 2020	11,930	₹10,000 SIP	Restarted — first SIP at high NAV
Dec 2021	17,200	Holding all cheap + expensive units	Holding only expensive units

By December 2023, Investor A's corpus from those 7 months of continued SIPs during the crash was worth approximately 3.1x the original investment — because each ₹10,000 invested at 7,600-9,800 NAV levels was worth ₹31,000+ at the 2023 levels. Investor B's resumed SIPs at 11,930 in October 2020 were worth approximately 1.5x by the same date. The gap between the 7 missed SIPs alone was significant — and that gap is exactly what the XIRR difference captures.

6Why We Make Emotional Decisions With Money

Understanding why the behaviour gap exists does not automatically close it — but it helps. Three well-documented cognitive biases drive most of the worst investment decisions:

Loss aversion

Losses feel approximately twice as painful as equivalent gains feel pleasurable. Seeing a portfolio down 20% creates psychological pain proportional to a 40% gain. This asymmetry drives panic selling and SIP pauses that are rational in terms of pain reduction but irrational in terms of wealth maximisation.

Recency bias

We overweight recent events when predicting the future. A 30% market crash in the last 3 months feels like the new normal — leading investors to expect continued decline and pause SIPs. In reality, no prolonged bear market in Indian equity has lasted more than 18-24 months before recovering to new highs.

Action bias

Doing something feels safer than doing nothing, even when doing nothing is the correct decision. Pausing a SIP feels like a responsible, proactive response to a market decline. In fact it is exactly backwards — the correct response to a correction, for a long-term investor, is inaction (or increased investment).

7The Discipline Premium: What Consistent Investors Actually Earn

Analysis of SIP data across major Indian market corrections — the 2008 global financial crisis, the 2011 Euro crisis, the 2015-16 emerging market selloff, the 2018 NBFC crisis, and the 2020 COVID crash — shows a consistent pattern: investors who continued SIPs through each full correction and recovery earned 1.5-3% more annually over the subsequent 5 years than investors who paused for 3+ months during those corrections.

This is the discipline premium — the additional XIRR earned purely by continuing to invest when the data and your emotions are both telling you to stop. It is not alpha from fund selection. It is not skill. It is the return generated by systematic inaction in the face of negative information.

The discipline premium compounds. 1.5-3% additional return per year over 20 years adds approximately 35-70% more to the final corpus compared to an identical investor who paused during each correction. No fund selection, no market timing, no financial sophistication required — just not stopping.

8How to Quantify Your Own Behaviour Gap

Knowing the behaviour gap exists is one thing. Measuring your own gap is another — and considerably more motivating. Here is how to do it:

1
Download your CAS from CAMS (camsonline.com) or KFin (kfintech.com). This lists every transaction in your mutual fund portfolio — every SIP, lumpsum, switch, and redemption with exact dates and amounts.
2
For each fund, calculate your XIRR using Excel's XIRR function. Enter all transactions as negative numbers (investments) and the current value as a positive number. The formula returns your annualised personal return.
3
Calculate the benchmark XIRR for the same cash flows. Use the Nifty 50 or the relevant category benchmark. Enter the same dates and amounts as your SIPs, but apply them to the index value on each date. The result is what you would have earned with identical cash flows into a passive index.
4
The gap between your fund's XIRR and the benchmark XIRR is your fund selection effect (positive or negative). The gap between the benchmark XIRR with your actual cash flows versus the benchmark XIRR with equal monthly investments is your behaviour effect — the behaviour gap.

9Making Discipline Structural: 5 Rules That Work

Willpower is unreliable. Structure is reliable. The investors with the smallest behaviour gaps are those who made their investment discipline structural — automatic and rule-governed — rather than volitional and market-responsive.

Auto-debit on salary credit day

Set SIPs to debit on the 2nd or 3rd of each month — the day after typical salary credit. The money is deployed before market anxiety can influence a decision.

Written investment policy statement

Write one paragraph: under what conditions you will pause, modify, or exit any investment. Most investors find the only legitimate conditions are: job loss, medical emergency, or the goal has been reached. This removes market movements as a valid trigger.

Standing lumpsum instruction

Pre-commit to investing an additional fixed amount if the Nifty falls 10% or more. This reverses the default (pausing when fearful) by making increased investment automatic.

Portfolio app off the home screen

FOMO and anxiety are both driven by visibility. Investors who check their portfolios daily make significantly more panic decisions than those who check monthly. Move the app two screens away from your home screen.

Annual review calendar

Schedule exactly two portfolio reviews per year — January and July. Between reviews, changes are not permitted unless a pre-defined trigger condition has been met. Calendar-based reviews replace reactive checking.

10How FundSageAI Shows You Your Behaviour Gap

FundSageAI computes your personal XIRR from your CAS — not the fund's trailing CAGR, but your actual return accounting for every transaction. It then shows this alongside the benchmark equivalent: what the same cash flows would have earned invested in the Nifty 50 index fund.

The difference between your XIRR and the benchmark XIRR is visible on your dashboard. It is the most honest number in personal finance — the cost of every pause, every switch, every delay you made in rupees and percentage points. Seeing it clearly is usually sufficient motivation to automate, and stop making it worse.

Sources & References

DALBAR QAIB (Quantitative Analysis of Investor Behaviour) 2024
SEBI investor survey 2023 — average SIP holding period data
AMFI monthly SIP registration and redemption data 2020-2024
Morningstar Investor Returns methodology documentation

Frequently Asked Questions

Can two investors in the same mutual fund really get different returns?

Yes — and the difference can be dramatic. XIRR (the correct return metric for staggered investments) accounts for the timing of each cash flow. Two investors can hold the same fund, over the same calendar period, but if one started SIPs earlier, added lumpsum during corrections, and continued without interruption, while the other started late, paused during downturns, and switched in and out, their XIRR can differ by 5-10 percentage points per year over a 5-7 year period. This is the documented behaviour gap — the difference between fund returns and investor returns. DALBAR's annual study shows the average equity fund investor earns 3-4% less annually than the funds they hold, purely due to behavioural decisions.

What is the behaviour gap in mutual fund investing?

The behaviour gap is the difference between what a mutual fund earns (its CAGR or rolling return) and what an investor in that fund actually earns (their XIRR). It arises because investors do not hold funds passively — they start, stop, switch, add, and withdraw based on market conditions and emotions. The gap typically opens during market corrections, when investors pause SIPs or exit, and closes unfavourably when they re-enter after markets have recovered, buying fewer units at higher prices. DALBAR's 2024 study shows the 20-year behaviour gap for US equity investors is approximately 2.8% annually. Indian data suggests the gap is similar or wider due to higher market volatility and shorter investment horizons.

What investment decisions create the biggest difference in XIRR for the same fund?

In order of impact: (1) Stopping SIPs during corrections — this is the single most damaging behaviour, eliminating cheap unit accumulation. (2) Redeeming and re-investing — each round-trip incurs tax and resets the cost basis higher. (3) Starting SIPs later than planned — time in market drives compounding more than timing the market. (4) Adding lumpsum investments at market peaks — concentrates investment at high NAVs. (5) Switching funds every 1-2 years — each switch resets the time horizon and loses low-base units. A disciplined investor who does none of these will dramatically outperform an identical fund-choice investor who does several.

Why does SIP timing matter if rupee cost averaging is supposed to remove timing risk?

Rupee cost averaging (RCA) does reduce timing risk compared to a single lumpsum — you buy more units at lower prices and fewer at higher prices. But RCA works only if you continue the SIP consistently through all market conditions. If you pause the SIP precisely when markets fall (which is when most investors pause), you eliminate the benefit: you miss the low-price unit accumulation that RCA provides. The investor who continued SIPs during March 2020 (Nifty at 7,600) accumulated units at a fraction of the 2021 prices. The investor who paused and restarted in October 2020 (Nifty at 12,000) got the same fund but paid 60% more per unit for those months of missed SIPs.

How can I calculate my personal XIRR to see how I am actually doing?

You need three things: (1) dates and amounts of every SIP and lumpsum investment, (2) dates and amounts of any redemptions, (3) current portfolio value as of today. Most mutual fund apps do not show XIRR prominently — they show absolute returns or trailing CAGR. To get your true XIRR: download your CAS (Consolidated Account Statement) from CAMS or KFin, which lists every transaction. Then use Excel's XIRR function or upload to FundSageAI, which computes XIRR automatically from your CAS data and shows it alongside the benchmark equivalent for the same period.

Is it too late to fix my behaviour gap if I have been investing sub-optimally?

It is never too late, but the earlier the correction, the more compounding time remains to benefit. The highest-impact immediate actions: (1) Set up auto-debit for all SIPs so they run regardless of your market view. (2) Set a written policy: you will not pause, modify, or exit any SIP until a specific trigger occurs (job loss, medical emergency). (3) Add a small lumpsum to each correction (Nifty falls 10%+) as a standing instruction. (4) Remove your portfolio app from your phone's home screen — visibility drives tinkering. The investors who recovered their behaviour gap fastest were those who made discipline structural through automation and rules, rather than volitional through willpower.

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