The scene
The scene
Nina had set up an automatic monthly investment of $500 two years ago. Every month on the same day, the transfer left her account and went into a diversified index fund tracking a broad equity market. She had not touched it. The automation was the point.
Then the market dropped. 8 percent in the first week. Another 12 percent over the next month. The total balance was now lower than what she had put in.
Nina paused the automation. The reasoning felt sensible. Why keep buying when the market was falling? Better to wait until things stabilised. Restart when the picture was clearer.
The market kept dropping for another two months, then started recovering. By the time Nina decided things looked stable enough to restart, the price was back above where she had paused. The months she had skipped were the months she would have bought at the lowest prices in two years. She had paused the automation precisely when the automation was most valuable.
She is not unusual. Behavioural finance research has documented this pattern: investors with automatic contributions to diversified long-term holdings consistently tend to interrupt those contributions during the periods when the price is most favourable for buying.
What your brain just did
What your brain just did
Our minds confuse "I am being prudent" with "I am avoiding the discomfort of seeing losses". Nina is not careless. Her brain converted fear into an action that felt sensible, the way all our brains do when we want to stop the pain of a paper loss. This behaviour has a name: Loss Aversion.
What to do instead, in one move
What to do instead, in one move
The behavioural research on dollar-cost averaging into diversified long-term holdings is consistent across decades. The strategy works precisely because it removes the timing decision. The moments when stopping feels most justified are usually the moments when continuing has the highest historical payoff. This is not a recommendation to do anything specific with your money. It is a pattern documented by research that anyone can read and consider, ideally with input from a licensed adviser in their country.
TL;DR
- Situation: You have an automatic monthly investment into a diversified long-term holding. The market drops. You feel pressure to pause until things settle.
- What your mind does: It weights the visible loss more heavily than the invisible benefit of buying at lower prices (this is called Loss Aversion, see below).
- Consequence: Pausing dollar-cost averaging into a diversified fund during a drop has historically tended to mean missing the lowest-priced buying months of a cycle.
- What to do: Many investors who follow research-based approaches commit in advance to never pausing automation during a drop, precisely because pausing then feels most justified.
What to do
- Many investors write down a rule before any volatile period: I will not pause my automatic contributions for any market move under X percent. The rule exists for the version of me that will feel scared.
- A common practice is to stop watching the price during volatile periods and let the automation do its work. The automation cannot be loss-averse. You can.
- Some people increase contributions during drops, treating the lower prices as a feature, not a bug. This is a personal choice that depends on circumstances.
- For larger portfolios or complex situations, consider consulting a licensed financial adviser before changing automation rules.
What not to do
- Do not pause automation because the market is dropping. The drop is when the automation is doing its most useful work.
- Do not confuse "this feels sensible" with "this is sensible". Loss aversion is felt as wisdom in the moment.
- Do not restart "when things look clearer". By the time things look clear, the prices are no longer favourable.
An automatic investment paused during a dip is automation that learned to stop working at the moment it mattered most.
Want to understand why this happens?
Loss Aversion is the brain's tendency to weight losses about twice as heavily as gains of the same size.
Dollar-cost averaging into a diversified fund is designed to bypass this bias. By committing to buy a fixed amount every month regardless of price, the strategy removes the human from the timing decision. The automation buys more units when the price is low and fewer when the price is high, without anyone needing to feel brave about it.
But the bias does not stay bypassed. When the market drops and the balance turns red, the loss aversion that the automation was designed to bypass shows up at the level of the automation itself. Pausing the automation feels like agency restored. It is, in fact, the bias defeating the system designed to prevent it.
Important context: this pattern applies specifically to broad diversified holdings like index funds. Individual company stocks are a different category. A single company can have specific problems (a scandal, a failed product, a structural change in its industry) that may justify reviewing the position. A diversified fund holds hundreds or thousands of companies. The probability that all of them have specific problems at the same moment is, by construction, much lower. Pausing dollar-cost averaging into a diversified fund during a market-wide drop is not the same decision as reconsidering a single company holding.
What the research found
Studies on investor behaviour during market drops have documented a consistent pattern: a significant portion of investors with automatic contributions to diversified holdings stop or reduce them during downturns, then restart when prices have recovered. The combined effect is buying high and not buying low, which is the opposite of what dollar-cost averaging is supposed to achieve.
Kahneman and Tversky's work on prospect theory explains the mechanism. The pain of watching contributions add to a falling balance is felt about twice as strongly as the joy of watching contributions add to a rising one. The brain reaches for a way to stop the pain. Pausing the automation stops the pain. That the pause also locks in the worst possible buying behaviour is invisible in the moment.
"Losses loom larger than gains. The pain of losing something we own is roughly twice as strong as the pleasure of gaining the same thing." — Daniel Kahneman and Amos Tversky (paraphrased from Prospect Theory, 1979)
This is called Loss Aversion. Daniel Kahneman and Amos Tversky, Prospect Theory: An Analysis of Decision under Risk (1979).
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