What Percentage of Your Returns Come From the Market's Best Days? The Honest Answer for Mutual Fund Investors

If you are already invested in mutual funds, you have probably seen this claim: miss the market's ten best days and your returns get cut in half. It is meant to scare you out of touching your investments, and it is widely misunderstood. Here is what it actually means, and why, for most people already invested, the answer is reassuring.

The Stat Everyone Repeats

The headline number is real. A ₹10 lakh investment tracking the Nifty 50 (total return) from 2005 to 2025 grew to about ₹1.43 crore if you stayed fully invested, but only about ₹67 lakh if you missed the index's ten best days. Half your wealth, gone, by sitting out ten days across twenty years. But there is a question hidden inside it.

How can you Miss Days if You are Holding?

If your money is invested and you never sell, how can you miss any day? You cannot. A buy-and-hold investor is present for every day, best, worst, all of them. The stat does not describe something the market does to you. It assumes an investor who sells, sits in cash, and buys back later, and happens to be on the sidelines when the best days arrive.

Those days are not scattered randomly; they cluster next to the worst ones. Seven of the Nifty's ten best days in the last twenty years came within two weeks of its ten worst days. 

This is why dodging a crash backfires: you sell after a sharp fall, the market snaps back days later, and you are still in cash for the recovery. Missing the best days is not bad luck; it is the cost of leaving.

The SIP Version of the Same Mistake

Most readers here do not invest a lump sum once. You invest every month through SIP (a Systematic Investment Plan, a fixed amount put into a fund at regular intervals). For you, leaving does not mean selling. It means stopping the SIP when the market falls.

That is worse than the lump-sum timer's mistake. The timer only misses the rebound; a SIP investor who stops also gives up cheap units. A SIP works through rupee-cost averaging: because the amount is fixed, it buys more units when prices are low and fewer when high. Falling months are when each rupee buys the most. Stop then, and you skip your cheapest purchases.

The Part the Stat Leaves Out: the Dip is the Discount

For a SIP investor, a crash is not the enemy. Consider a simplified illustration (not real fund data), with ₹10,000 invested each month:

An investor who keeps going invests ₹50,000, ends with 578.1 units, and has an average cost of ₹86.49 per unit. One who pauses in months 3 and 4, the cheapest months, invests ₹30,000, ends with 317.6 units, and has a higher average cost of ₹94.46. The dip bought the most units per rupee; skipping it raised the average price paid.

Real data points the same way. Across decades of Indian mutual fund data, investing every year at the market's absolute peak versus its absolute bottom over 25 years changed long-term returns by only about 1% a year, and a plain monthly SIP earned nearly the same. In 2020, many funds fell around 38% yet went on to deliver over 14% annualised afterwards, and continuing a SIP through the fall lowered the average cost per unit. INDmoney's own breakdown of a ₹10,000 SIP through the 2020 crash shows the same: the investor who kept going gathered far more cheap units than the one who paused and restarted a few months later.

People Really Do Quit at the Bottom

This is not hypothetical. During the March 2020 crash, the SIP closure ratio jumped to 70%, well above that year's average of about 57%. When volatility returned in late 2024, the stoppage ratio rose to 109% in January 2025, from about 83% a month earlier, driven mainly by fear during the correction. Lump-sum investors do the same, later: redemptions in 2020 and 2023 lagged the correction, so investors exited after the damage was already done. In both cases, people leave near the bottom, right before the days that matter most.

Two Things to Get Straight

First, staying invested does not mean trying to time the dip cleverly. The lesson is not to start guessing in the other direction by buying big at the lows. It is not to leave what you were already doing.

Second, the stat is one-sided, and it helps to know why. As one analysis notes, you could just as easily build a "miss the ten worst days" table that argues the opposite, that timing is brilliant. The point is not that the best days are special. It is that being out of the market, in either direction, is a gamble you do not need to take.

Things to Keep in Mind

This reasoning assumes a sensible, diversified fund. Recovery is not guaranteed in every single fund, though diversified equity funds have historically recovered from every major crash. 2008 took about two years, and 2020 was faster. Staying invested is not a reason to hold a badly chosen fund forever; it is a reason not to abandon a good one out of fear. And the real risk for a SIP investor is not picking the wrong date; it is missing instalments, which removes the averaging benefit the SIP exists to give.

The Bottom Line

The market's best days are not something it can take from you. You can only give them away by leaving. For a lump-sum investor, that means not selling in a panic. For SIP investor, it means not stopping when the market falls. Same decision, same reason.