Behavioural Finance for Swiss Investors — The Five Biases That Destroy Returns

The most expensive assumption in investing: "I'm rational about money." Decades of research say otherwise — for everyone, professionals included. The difference between investors who compound and investors who churn is not intelligence; it's whether their process assumes the biases exist and routes around them. Five patterns, each with the rule that defuses it.

1. Loss aversion

Losses hurt roughly twice as much as equivalent gains feel good. The behavioural output: selling after falls (to stop the pain) and hesitating after crashes (when expected returns are highest) — buying high and selling low, implemented by instinct.

The rule: decide drawdown behaviour in advance, in writing (the IPS drawdown clause), and automate contributions so buying continues without requiring courage.

2. Recency bias

Whatever happened lately feels like the new permanent state. Three good years make risk feel obsolete; a crash makes recovery feel impossible. Portfolios drift aggressive at tops and defensive at bottoms — precisely backwards.

The rule: a fixed target allocation with mechanical rebalancing. The calendar, not the recent past, decides when you buy what.

3. Home bias

Investors everywhere overweight their home market, and Switzerland makes it seductive: a strong currency, world-class companies. But the Swiss equity market is a small slice of global market value, concentrated in a handful of mega-caps — and your salary, property and pension already depend on the same economy. Overweighting it stacks risk on risk.

The rule: global diversification as the default; any Swiss overweight should be a sized, deliberate decision, not familiarity wearing a strategy's clothes.

4. Overconfidence

The better your career is going, the more dangerous this one is. Competence transfers; edges don't. High earners systematically over-trade, concentrate positions (often in their own employer — doubling the payroll risk they already carry) and mistake a bull market for skill.

The rule: cap single positions — above all employer stock — and measure your actual returns against a boring global benchmark once a year. The spreadsheet is humbling, and cheaper than the alternative.

5. Inaction

The quiet one, and in our experience the most expensive in Switzerland: the unfilled 3a, the cash "waiting for the dip" through a decade-long rise, the pension certificate unread since 2019. Every other bias destroys money visibly; this one destroys it as a counterfactual, so nobody mourns it.

The rule: default everything to automatic — contributions, 3a top-ups, rebalancing dates — so that doing the right thing requires no decision, and only stopping does.

What are you optimising for?

Notice the shape of all five rules: none requires better judgement in the moment. Each replaces judgement-in-the-moment with a structure built earlier. That's the entire practical lesson of behavioural finance — not "know your biases" but "build a system your biases can't operate."

Control question: which of the five is costing your household the most right now? (If nothing comes to mind, the answer is almost always number five.)