At some point in the investment process — especially early on — a downturn arrives. It may be 10%, 20%, or more. In that moment, the portfolio that in theory was a calm, rational decision becomes a source of anxiety. The urge to do something is powerful.
What separates the investor who achieves good long-term results from the one who does not is not the ability to predict when markets will fall: nobody does that consistently. It is the ability not to react destructively when they do.
Volatility Is Not a System Failure
Volatility — the frequent fluctuation of asset prices — is not a market anomaly. It is the market’s natural condition.
Equity markets have historically experienced corrections of 10% or more roughly once every one to two years. Corrections of 20% or more — what is technically called a bear market — have occurred approximately every four to five years. Large crises, like those of 2000, 2008, or 2020, happen less frequently but do happen, and they always seem impossible to have predicted in retrospect.
This pattern is not an accident. Volatility is the compensation that markets pay investors for assuming risk. If the stock market rose steadily and predictably at all times, the expected return would be similar to that of risk-free assets. The superior long-term returns that equities have historically offered exist precisely because they involve navigating uncomfortable periods.
Understanding this does not eliminate the discomfort of watching a portfolio fall. But it changes the mental frame: downturns are not signals that something is broken. They are part of the deal.
Why Our Brains React Badly
The human brain is not well adapted for long-term investing. It is adapted for short-term survival, and losses matter to it more than equivalent gains.
This phenomenon, extensively documented in behavioral psychology, is known as loss aversion. Losing 1,000 euros generates approximately twice as much emotional distress as gaining 1,000 euros produces satisfaction. In evolutionary terms this makes sense: losing resources in a scarcity environment was more dangerous than failing to acquire them. In investment terms, it leads to poor decisions.
The practical consequence is that during a market drop, the brain interprets the decline as a danger signal and generates an urgency to act in order to “protect itself.” This urgency manifests as the impulse to sell, reduce exposure, or “wait for things to stabilize” before reinvesting.
The problem is that this impulse works exactly backwards from what is actually useful: selling during downturns locks in losses and frequently causes the investor to miss the recovery. Studies on individual investor behavior consistently show that actual returns achieved are significantly lower than those of the index they are invested in, precisely because they buy late and sell early.
The Most Costly Mistakes During Downturns
Selling to “prevent further losses.” The logic seems obvious: if something is falling, sell before it falls further. The problem is that nobody knows when the bottom occurs. The moments of greatest panic and strongest temptation to sell tend to be exactly the moments closest to the bottom of the downturn. Whoever sold in March 2020 — when the S&P 500 fell 34% — missed the 70% recovery in the months that followed.
Waiting for the “right moment” to get back in. After selling during a downturn, the investor who waits for the perfect moment to return usually misses it. Markets do not announce themselves before recovering. The best trading days of the year tend to occur during periods of highest volatility. Being out of the market during those days carries a disproportionate cost to total return.
Checking the portfolio too frequently. How often you look at your portfolio has a direct impact on your anxiety level and your tendency to act. A classic study showed that investors who review their portfolio daily experience losses 41% of days (because markets go up and down), while those who review annually “experience losses” only 13% of the time — even though the portfolio is exactly the same.
Changing strategy at the worst moment. Downturns prompt strategy reviews. The result is usually abandoning the approach that was working — because it seems not to be working — and adopting another that also will not work when its moment comes.
Strategies for Staying the Course
The key is not to eliminate the emotional reaction — that is impossible — but to create structures that prevent that reaction from translating into destructive decisions.
Define your strategy in calm, before the storm. Write down explicitly: your time horizon, how much of a decline you are willing to absorb without selling, what percentage of each asset type you hold. This written declaration, made during a period of market calm, acts as an anchor when the market falls and the brain searches for reasons to change course.
Automate your contributions. If you invest a fixed amount each month regardless of what the market does — what is called dollar-cost averaging — you disengage from the game of timing. When the market falls, you buy more units with the same money. When it rises, you buy fewer. The long-term result tends to be more favorable than trying to pick the right moments.
Reduce the frequency of review. Review your portfolio monthly or quarterly at most. Daily review provides no useful information and introduces unnecessary anxiety.
Be clear about the time horizon. An investor with a 20-year horizon should evaluate their portfolio in terms of 20 years, not the last 3 months. A 25% drop in a year is irrelevant if the goal is two decades away and the asset has historically generated positive returns over long periods. Time horizon is the filter that turns drama into noise.
When Volatility Is Your Ally
Volatility has a side that is rarely mentioned: it is the condition that makes it possible to buy assets at prices below their long-term value.
An investor with regular contributions and a long time horizon sees market downturns differently: they are months when more units are purchased for the same money. If you believe that in 15 years the market will be higher than it is today — which is what history suggests, though it does not guarantee — then today’s low prices are an opportunity, not a threat.
This perspective is not easy to maintain during an actual downturn. But it is conceptually correct and becomes more accessible with practice and with the passage of time.
Volatility is not the long-term investor’s enemy. The real enemy is the poorly managed emotional reaction to volatility. Understanding this mechanism, preparing for it, and having a plan that prevents impulsive action during downturns is probably the most valuable skill that anyone who invests for the long term can develop.
