Market volatility: Why instinct alone is not enough in market decision-making

Here is a small experiment. Imagine two yellow lines drawn on a railway track, one closer to you, one farther away. Which one looks longer? Almost everyone says the farther one. But both lines are exactly the same length. What makes it truly unsettling is this: even after you know it is an illusion, you cannot unsee it. The brain keeps getting it wrong.

Investing in uncertain markets works the same way. Our instincts consistently mislead us at the moments that matter most. And just like the optical illusion, knowing about the bias is not enough. You need the investing equivalent of a ruler. You need frameworks.

What the data actually says

Equities fall 10 to 20% in almost every calendar year. And yet, over the last 46 years, 37 of those years have still closed positive. Over any rolling 7-year period in Indian equity markets, there have been zero instances of negative returns. In 85% of cases, annualised returns came in above 10%. Even the brutal 30 to 60% corrections have historically recovered within 1 to 3 years. What feels catastrophic in the moment tends to look unremarkable in hindsight.

The six ways investors get in their own way

The same behavioural patterns repeat with remarkable consistency. Think of them as the six Ps of behavioural error.

Panic Selling when markets fall. The sharpest rallies almost always arrive when sentiment is at its worst , the investors who stepped out to protect themselves are precisely the ones who miss the recovery. Profit Booking at all-time highs, as though a new high is a ceiling rather than what progress looks like in a growing economy. Procrastination , there is always a reason not to invest, and waiting for the list to clear means missing most of the growth. Panic Buying driven by fear of missing out, which pushes investors into assets at precisely the wrong valuations. Expert Predictions , at any point in time someone credible is forecasting a crash, and acting on those forecasts requires getting two calls right every single time. And finally, Performance Chasing: buying yesterday’s trade at a premium, usually just as the outperformance cycle ends.

Fear and greed, when you get down to it, produce the same outcome: you sell when prices are low and buy when they are already high. Repeat that a few times and the damage to compounding is slow, quiet, and largely invisible until it is too late.

The real problem is not knowledge , it is implementation

Most investors who make these mistakes are not uninformed. They know panic selling is bad. They know timing the market is nearly impossible. And then the market falls 20% in three weeks, and they sell anyway. This is the optical illusion problem all over again , knowing about the bias does not make it disappear.

Warren Buffett put it best: “To invest successfully, one doesn’t need a stratospheric IQ. What’s needed is a sound intellectual framework for making decisions and the ability to keep emotions from corroding that framework.” The solution is not better knowledge. It is a better structure.

Structure beats instinct

• Tie your investments to actual goals , a home purchase in ten years, a child’s education, retirement. Goals do not panic. When your portfolio is anchored to something real and time-bound, it becomes far harder to dismantle it because the Sensex had a bad quarter.
• Investing a fixed amount every month through a SIP removes the hardest decision: when to enter. You stop looking for the right moment because you have already decided there is no such thing. You are always in, always compounding, buying more units when prices are lower without any emotional effort.
• Have an Opportunity Playbook, and write it down before the crisis arrives, when your head is still clear. Not a vague intention to "stay calm," but an actual playbook. Set aside a portion of your safer assets, debt, cash, or equivalents, specifically earmarked for moments of market stress. Then decide in advance, with precision, how you will deploy it, for instance, moving a tranche into equities at a 10% market decline, another at 20%, and so on, at progressively deeper corrections
• Have rebalancing rules that force you to do the opposite of what instinct recommends. And document all of it in an Investment Policy Statement so the plan exists outside your head, ready for the moments when emotions are loudest.
• A good adviser’s value in volatile times is not picking better funds. It is being the voice in the room that says ‘don’t do anything’ when everything feels urgent.

None of this requires prediction.

You do not need to know what markets will do next month. You need to know what you are investing for, build a structure around that, and not dismantle it every time things get uncomfortable. The optical illusion does not go away. But with a ruler in hand, it stops mattering.

The hardest skill in investing is not analysis. It is staying in the room when everything in you says to leave , not because you are ignoring the discomfort, but because you built a structure that does not require you to act on it. That is where the returns are.

Before I sign off, here are three things worth doing, not just reading about.

• Build evidence-based frameworks for the investment decisions you will inevitably face.
• Put them in an Investment Policy Statement, a written plan holds firmer than a mental one. Consult your dedicated advisor for a better framework.
• Know your 6 Ps. The mistakes are predictable. That means they are also preventable.

The author is Group CEO, FundsIndia. Views Expressed are personal.