Investors often say they want to buy low and sell high. Yet, when markets rise, they rush to invest. When markets fall, they hesitate, stop their SIPs or move their money to safer investments. Why do we repeatedly do the opposite of what we know is right?

Imagine two investors, Amit and Rohan, who start investing in mutual funds around the same time.

Amit invests ₹10,000 every month through a systematic investment plan (SIP). When the Nifty rises, he continues investing. When the market corrects by 15%, he continues investing. He does not particularly enjoy watching his portfolio turn red, but he sticks to his plan.

Rohan takes a different approach. He waits for the right opportunity. When the market is rising, he worries that he is missing out and starts investing. His investments perform well initially, reinforcing his decision. But when the market falls by 15%, he becomes uncomfortable. He postpones his next investment, stops his SIP and decides to wait until things improve.

A few months later, the market begins recovering. Rohan waits for confirmation that the worst is over. By the time, he feels confident enough to invest again, prices have already risen considerably.

Amit has been buying throughout the journey. Rohan has been buying when markets look attractive to everyone else and holding back when prices are lower.

Neither investor necessarily lacks financial knowledge. The difference lies in how they respond emotionally to market movements.

Investors often know they should buy low and sell high. The problem is that falling markets rarely feel like buying opportunities, while rising markets make buying feel safe.

This is one of the most persistent contradictions in investor behaviour.

1. Why Rising Markets Make Us Want to Invest More

Consider what happens when the stock market has delivered strong returns for several months.

Your colleague mentions that his mutual fund portfolio has grown by 18%. A friend talks about making money in small-cap funds. Social media is filled with discussions about stocks hitting record highs. Even people who previously avoided equities begin asking which mutual fund they should invest in.

Suddenly, investing feels easy.

There are several behavioural reasons behind this shift.

Recency bias: Assuming the recent past will continue

Recency bias is our tendency to give disproportionate importance to recent events when forming expectations about the future.

If the Nifty 50 has risen consistently over the past six months, investors may begin believing that markets will continue rising. Recent returns become their reference point for what constitutes a normal return.

A mutual fund that delivered 25% over the previous year starts looking attractive. A fund that delivered 10% appears disappointing, even if the latter has a more suitable investment strategy or a different risk profile.

Investors begin chasing yesterday's winners in the hope of replicating their performance.

The problem is that past returns tell us what happened, not what will happen next.

Markets can continue rising for extended periods, but they can also correct sharply after a strong rally. Recent performance alone cannot tell us which outcome lies ahead.

Fear of missing out: Everyone seems to be making money

Fear of missing out, commonly known as FOMO, is another powerful influence.

Imagine that the Nifty has risen 20% over a year. You have kept ₹5 lakh in a savings account because you were uncertain about investing in equities.

Your friends, colleagues and relatives have been discussing their investment gains. Every conversation makes your decision to stay out feel worse.

You begin thinking, "If I had invested last year, I would have made a substantial profit. What if the market rises another 20%?"

The fear of missing further gains becomes stronger than the fear of losing money.

You invest the ₹5 lakh, not because you have assessed your financial goals, risk tolerance or asset allocation, but because you do not want to be left behind.

This is how investors often enter markets after a significant rally.

FOMO changes the question from "Is this investment suitable for me?" to "How much more money could I make if I don't invest now?"

That is a very different basis for making a financial decision.

2. Why Falling Markets Make Us Stop Investing

Now consider the opposite situation.

The market falls 15%. Your ₹10 lakh equity portfolio is suddenly worth ₹8.5 lakh. News channels discuss slowing economic growth, foreign investors are selling, and market experts debate whether a larger correction is coming.

The same investor who was eager to invest when the market was rising now hesitates.

The reasons are equally powerful.

Loss aversion: Losing money hurts more than making it feels good

Behavioural economists Daniel Kahneman and Amos Tversky demonstrated that people tend to experience losses more intensely than equivalent gains. This principle is known as loss aversion.

For many investors, the emotional pain of losing ₹1 lakh is greater than the pleasure of gaining ₹1 lakh.

Consider an investor whose portfolio rises from ₹10 lakh to ₹12 lakh. The ₹2 lakh gain feels rewarding.

Now imagine that the portfolio falls from ₹12 lakh to ₹10.5 lakh.

Although the investor still has ₹50,000 more than the original investment value, the recent decline of ₹1.5 lakh may dominate their thinking.

They may feel that something has gone wrong, even though the portfolio remains above its starting value.

This emotional response influences subsequent decisions.

The investor may stop the SIP, postpone additional investments or sell existing holdings to prevent further losses.

The irony is that the investor becomes reluctant to buy more units precisely when the same monthly contribution can purchase more units at lower prices.

Of course, a falling market does not automatically make every investment attractive. The important distinction is between reassessing an investment because its fundamentals have deteriorated and avoiding investments simply because prices have fallen.

The ambiguity of uncertainty: What if things get worse?

When markets fall, investors rarely know how far they will decline.

A 10% correction might be followed by a recovery. It might also be followed by another 20% decline.

This uncertainty makes waiting feel sensible.

An investor tells himself, "Let the market stabilise. I'll invest once the situation becomes clearer."

The problem is that markets rarely announce when they have reached the bottom.

By the time economic data improves, corporate earnings recover and sentiment becomes positive, stock prices may already have rebounded.

Waiting for certainty can mean missing a meaningful part of the recovery.

This does not mean investors should blindly invest every time markets fall. It means that waiting for a clear signal can be an unreliable strategy when the signal itself depends on information that markets continuously absorb.

3. The Paradox of Buying High and Selling Low

Let's use a simplified example to understand the financial implications of this behaviour.

Suppose a mutual fund's NAV is ₹100. An investor starts a monthly SIP of ₹10,000.

When the NAV rises to ₹125, the investor becomes enthusiastic and increases the investment to ₹20,000.

Later, the market corrects and the NAV falls to ₹90. Concerned about further losses, the investor reduces the SIP to ₹5,000.

At a NAV of ₹90, the investor can purchase more units with ₹10,000 than at ₹125. Yet the investor has reduced the contribution precisely when the same amount would buy more units.

Let's compare the units purchased with a fixed ₹10,000 investment at different NAVs.

The table illustrates a basic principle: when the NAV falls, a fixed investment purchases more units.

This is one of the benefits of rupee-cost averaging through an SIP. Investors accumulate units at different prices instead of committing their entire investment at a single point.

However, there is an important qualification.

Buying more units at a lower NAV does not guarantee better returns. A fund's NAV can continue falling, and the underlying investments may deteriorate. The benefit depends on the eventual performance of the assets held.

Nor does an SIP guarantee profits or protect investors from market losses.

The real advantage of disciplined investing is that it reduces the need to repeatedly predict market movements.

Unfortunately, investors often abandon this discipline when it becomes most psychologically difficult to maintain.

4. Herd Mentality: Why Other Investors Influence Our Decisions

Investment decisions rarely happen in isolation.

When markets rise, people notice the gains being made by others. When markets fall, they notice the fear and pessimism around them.

This creates a powerful feedback loop.

During a bull market, rising prices attract attention. More investors enter the market, helping reinforce positive sentiment. As prices continue rising, even more people become interested.

During a downturn, the reverse can happen. Falling prices generate anxiety, investors withdraw money or reduce fresh investments, and pessimism spreads.

This behaviour is known as herd mentality.

Consider the surge of interest in small-cap mutual funds during periods when small-cap stocks deliver strong returns. Investors may begin selecting funds based on recent performance, sometimes without adequately considering valuations, portfolio concentration or their own ability to withstand volatility.

When the segment subsequently corrects, the same investors may question whether they should have invested at all.

The issue is not that small-cap funds are inherently unsuitable. They can play a role in appropriate portfolios. The problem arises when investors choose an asset class because everyone seems to be making money from it, rather than because it serves a clearly defined financial objective.

Herd behaviour makes investors feel reassured when everyone agrees with them. Unfortunately, widespread enthusiasm or widespread fear does not necessarily indicate whether an investment is attractively priced.

5. Mental Accounting: Why We Treat Gains and Losses Differently

Another behavioural tendency that influences investment decisions is mental accounting.

We often assign different emotional meanings to money depending on where it came from or how it has performed.

Suppose you invested ₹2 lakh in an equity mutual fund. After a strong rally, it grows to ₹2.5 lakh.

You may feel comfortable taking additional risks because you consider the ₹50,000 gain to be money you have earned from the market.

Now suppose the portfolio falls to ₹2.2 lakh. You may feel compelled to protect the remaining gain, even though your investment is still worth more than the original ₹2 lakh.

Alternatively, if the portfolio falls below ₹2 lakh, you may refuse to invest further because you do not want to increase your exposure to an investment that has already lost money.

Both reactions can be problematic.

Your portfolio's suitability should depend on your financial goals, investment horizon, asset allocation and the quality of the underlying investments, not simply on whether you are currently sitting on a profit or a loss.

Money does not become fundamentally different because you label it a gain, a loss or a bonus.

Yet these mental categories can strongly influence financial decisions.

6. How Can Investors Avoid This Behavioural Trap?

The objective is not to become emotionless or predict every market movement correctly. It is to create an investment process that prevents temporary emotions from repeatedly disrupting long-term decisions.

Here are five practical steps.

1. Automate your investments.

If you have selected an appropriate mutual fund portfolio and determined a sustainable monthly contribution, automate your SIPs.

Automation reduces the number of occasions on which you must decide whether the market looks attractive.

However, automation should not replace periodic reviews. If your income, financial goals or risk capacity changes, your investment plan may need to change as well.

2. Decide your asset allocation before markets become volatile.

Suppose you have ₹20 lakh in financial investments, with 60% allocated to equities and 40% to debt.

If equities fall sharply, your allocation may move away from your intended mix. A pre-defined rebalancing approach can help you decide whether to restore the original allocation, rather than making decisions based on fear.

The appropriate allocation depends on your goals, investment horizon, liquidity requirements and risk tolerance.

3. Separate market movements from changes in fundamentals.

A falling market is not, by itself, proof that you should sell. Equally, a lower price does not automatically make a stock or fund worth buying.

Ask whether the investment thesis has changed, whether the portfolio remains suitable and whether your original assumptions still hold.

A temporary market correction and a permanent deterioration in an investment require different responses.

4. Stop checking your portfolio too frequently.

If you have a long investment horizon, checking your portfolio several times a day can magnify short-term emotional reactions.

A daily decline may feel significant even when it has little bearing on a financial goal that is 10 or 15 years away.

Review your investments at a frequency appropriate to your circumstances, rather than allowing every market movement to become a decision-making event.

5. Write down your investment rules in advance.

Decide how you will respond to a market correction before one occurs.

For example, you might commit to continuing your planned SIPs during ordinary volatility, reviewing your asset allocation periodically and avoiding large discretionary investments based solely on recent returns.

These rules should not be rigid. They should provide a framework for rational decisions when emotions run high.

The aim is to make fewer impulsive decisions, not to eliminate judgement.

The Bottom Line

Investors rarely struggle because they have never heard the advice to buy low and sell high. They struggle because the psychological conditions required to follow that advice are uncomfortable.

When markets rise, optimism makes risk appear manageable. When markets fall, fear makes even reasonable investments look dangerous.

Recency bias encourages investors to extrapolate recent returns. FOMO pushes them to follow the crowd. Loss aversion makes falling portfolios painful, while herd mentality reinforces both enthusiasm and panic.

The result is a familiar pattern: investors become more willing to buy after prices have risen and less willing to invest after prices have fallen.

The solution is not to assume that every correction is a buying opportunity or that markets always recover quickly. Some investments never regain their previous highs, and some declines reflect genuine economic or business deterioration.

Instead, investors need a disciplined process that distinguishes market noise from meaningful changes in fundamentals.

For a long-term investor, the most useful question during a market correction may not be, "How much further can the market fall?"

It may be, "Has anything changed about my financial goals, my ability to take risk or the reasons I chose these investments?"

That question will not tell you where the market will bottom. Nothing can reliably do that.

But it can help you avoid allowing fear, excitement and the behaviour of others to dictate every investment decision.

After all, successful investing is not simply about knowing when to buy. It is about having a plan you can continue to follow when buying feels frightening and holding cash feels comforting.