Missing the best days

A red morning a few weeks ago. Market down about four percent by 10am, and the group chat was already moving. Three different people said the same thing. Moved to cash, will get back in once it settles. Sounded responsible. Felt smart.

I pulled twenty years of numbers that night.

Take Rs 10 lakh, leave it fully invested for two decades at an illustrative twelve percent, and it grows to roughly Rs 96 lakh. Now sit out just the ten single best days across those twenty years, parking that money in cash on each one. You land closer to Rs 47 lakh. Half. Miss twenty of the best days and you are down near Rs 29 lakh. Thirty, and you are at Rs 18 lakh.

Ten days. Out of roughly five thousand trading days. Two tenths of one percent of the calendar deciding half the outcome.

Here is the part the move-to-cash plan never accounts for. The best days do not stand politely apart from the worst ones. They cluster in the same panicky stretches, most of the biggest up-days landing within a couple of weeks of the biggest down-days. The exit that dodges the crash is usually the same exit that skips the snapback. You do not get to keep one and avoid the other.

Which is the quiet case for a SIP. It does not read the news. It does not feel the red. It buys on a date, not a mood, automatic and boring and always in. In a scary week that is not a weakness. That is the whole edge.

The crash you sat out and the rally you missed were the same week.

I ran it again on the last two years

Twenty years is a long, abstract window. So I ran the same test on something everyone reading this lived through: the Nifty 50 from 14 October 2024 to 9 October 2026, using NSE's daily closing data. That is 493 trading days, counting the two Budget day sessions. The index fell over the stretch, from 25,127.95 to 22,520.45, which makes it a harder test, not an easier one.

Put Rs 1,00,000 into the index at the first close and simply hold it, with no dividends and no costs, and it ends at Rs 89,623. Now take out the best and worst days one at a time, as if you had been in cash on exactly those sessions.

Look at the last two rows together. Dodging the ten worst days would have been worth a lot. But if your exits also cost you the ten best days, which is what usually happens, you end up at Rs 89,370, a little below someone who did nothing at all. You took every risk of trading and kept none of the reward.

Why the good days hide inside the bad weeks

It is not luck. Big up days need a big down day in front of them, and they happen when fear is highest, because that is when prices have room to snap back. In the two years of data, six of the ten best days came within six trading sessions of one of the ten worst. Here is March and April 2026, day by day.

1. 19 Mar 2026Nifty down 3.26%

   The worst day in the two years.

2. 23 Mar 2026Down 2.60%

   Two sessions later, another heavy fall.

3. 24 Mar 2026Up 1.78%

   The very next day: one of the ten best.

4. 30 Mar 2026Down 2.14%

   Month end close of 22,331.40, about 11% below February's.

5. 8 Apr 2026Up 3.78%

   Five sessions after that close: the second best day in two years.

April 2025 told the same story: down 3.24 percent on 7 April, then up 1.92, 2.19 and 1.77 percent on 11, 15 and 17 April. Anyone who moved to cash after the first week and waited for calm missed most of the repair.

Do the long version on your own numbers

The opening used twenty years at an illustrative 12 percent. The arithmetic behind it is simple: every best day you miss divides your final value by one plus that day's gain. Change the inputs below to see how fast it adds up. The default best day gain is the average of the ten best Nifty 50 days in the two years above, 2.41 percent. Longer histories have bigger best days, so this is a mild version.

The free Learn module on why investors lose calls this the behaviour gap and walks through the biases that drive it, with a quiz and a certificate. To see what regular buying does with the same falls, try the SIP calculator, then read why pausing a SIP in a downturn is the most expensive instinct. For the 26 year version of this test, read the ten days that mattered.