All the math in this course is correct. None of it matters if you can’t follow it during a panic. Daniel Kahneman (Nobel 2002) and the behavioral finance tradition established this decades ago: humans are systematically bad at decisions under uncertainty, in predictable ways.
Today’s lesson is the main biases, their specific manifestations in Italian investing contexts, and the defenses that actually work.
Loss aversion — the big one
Loss aversion: people feel losses roughly 2× more strongly than equivalent gains.
Losing €100 hurts about as much as gaining €200 feels good.
Manifestations
- Panic selling during drawdowns. A 40% drop feels like a catastrophe; you want the pain to end. You sell. You lock in the loss.
- Reluctance to take losses. Holding losing positions too long “hoping to break even.” Classic retail behavior.
- Risk aversion in portfolio construction. Holding too much cash/bonds because the potential gain from equity feels unappealing vs the risk of a loss.
Italian-specific example
2008 crisis: many Italian retail investors sold Italian equities at the bottom (FTSE MIB -58%). Specifically from March 2009, tens of billions of euros left equity funds in Italy. Those funds fled to bonds and cash. By 2013, Italian equities had recovered most losses. The sold-at-bottom investors locked in the loss permanently.
Defense
- Pre-commit to not selling during crises. Written plan. Look at it when scared.
- Appropriate allocation. If 40% drawdown is psychologically unbearable, hold less equity — even at cost of expected return. Sleeping is more important than mathematical optimization.
- Don’t look at your portfolio during panics. Seriously.
Recency bias
Recency bias: overweighting recent events when predicting future.
If equities have risen 20% in the last year, people extrapolate 20% forward. If they fell 30%, people extrapolate 30% further declines.
Manifestations
- Chasing recent winners. 2021: tech stocks up huge → flood into tech funds. 2022: tech down. Retail bought high.
- Avoiding recent losers. Italian stocks unloved for years → Italians under-invest in Italy despite valuations improving. (Fine for global diversification, but the behavioral pattern is the point.)
- Crypto booms. 2017, 2021 peaks coincided with mass retail entry. Recency drove investment at worst times.
Italian-specific example
2021: Moncler, Ferrari, Brunello Cucinelli stocks soared 40-60%. Retail piled in. By 2022, Moncler down 30%. Retail bag-holders.
Defense
- Remember mean reversion. What’s gone up a lot typically returns less going forward.
- Index diversification. Removes the need to make “what’s hot right now” decisions.
- Look at long-term data, not headlines. A chart going back 100 years calms recency reactions.
Confirmation bias
Seeking information that confirms existing beliefs, dismissing information that challenges them.
Manifestations
- Following like-minded sources. If you believe crypto is the future, you follow only bulls. You miss skeptics.
- Interpreting ambiguous data favorably. Your stock’s bad quarter “was due to temporary factors.” Another stock’s bad quarter “shows fundamental problems.”
- Motivated reasoning on holdings you own. You bought XYZ; you find reasons it’ll go up. You didn’t buy ABC; you find reasons it won’t.
Italian-specific example
2020: many Italian retail investors bought Eni at €7-8 because “oil is at a historical low, it’ll recover.” Confirmation came from oil news. By 2024, Eni had recovered but slowly; investors who concentrated heavily got a mediocre outcome vs diversification.
Defense
- Deliberately seek dissenting views. If you own a stock, read bearish analyses.
- Write down your thesis before buying. Revisit quarterly. Is the thesis still valid?
- Acknowledge you might be wrong. Humility is a diversification strategy.
Herding / FOMO
The tendency to follow what “everyone else” is doing.
Manifestations
- Buying what’s popular. Friends talking about crypto → buy crypto.
- Selling when everyone sells. Panic across social media → sell.
- Following influencer recommendations. Parallels real communities making identical bets.
Italian-specific example
Post-2020, “NFT trading” became a Milan social topic. Many white-collar professionals bought NFTs as speculative investments. Most lost 80-95% by 2022. Herding at work.
Defense
- Be suspicious of consensus. The easier a trade feels, the more crowded and expensive it is.
- Do your own math. If something requires you to believe in hype to make the math work, it’s hype.
- Wait out mania phases. FOMO is real but fleeting.
Anchoring
Over-relying on the first number you see.
Manifestations
- Anchoring to purchase price. “I bought XYZ at €100. I won’t sell below €100.” The stock’s current value has nothing to do with what you paid.
- Anchoring to a benchmark price. Italian housing: many refuse to sell a house at “less than what I paid” even when market has moved. Opportunity cost ignored.
- Anchoring during negotiations. A high initial asking price anchors the bargaining range favorably for the seller.
Italian-specific example
Italian property sellers during 2011-2016: many kept unrealistic asking prices based on 2007 purchase prices. Houses sat on the market for years. By the time they accepted reality, the market had moved further. Anchoring cost them.
Defense
- Evaluate current decisions based on current facts, not past actions. The €100 you paid is a sunk cost. Decide what to do today based on today’s conditions.
- Write down rationale separately from prices. Decisions should follow thesis, not price history.
Availability heuristic
Overweighting what easily comes to mind.
Manifestations
- Overestimating dramatic risks. Recent terrorist attacks → feel unsafe flying. Statistically flying is safer.
- Underestimating gradual risks. Inflation eats savings silently; less vivid than a stock crash, therefore underweighted.
- Misjudging likelihood of success. Remembering lottery winners and Silicon Valley billionaires (vivid), ignoring the millions who failed (invisible).
Italian-specific example
Italian housing boom 2000-2008: vivid, widely-publicized “amici che hanno fatto fortuna” narrative. Most ignored that the inflation-adjusted returns of Italian housing weren’t particularly impressive over long periods.
Defense
- Rely on base rates, not vivid examples. The average outcome matters more than the outlier.
- Diversify across asset classes. Don’t concentrate based on “story” assets.
Endowment effect
You value things you own more than the same thing you don’t own.
Manifestations
- Refusing to sell losers. You own a stock at a 30% loss; you wouldn’t buy it today at this price. But because you own it, you hold.
- Overpricing personal property. Your house is worth more than the market’s opinion of it (in your mind).
- Sticking with bad financial products. Fondi comuni you’ve had for years feel “part of you”; you won’t switch despite unfavorable math.
Defense
- The “would I buy today” test. Imagine you have cash instead of this asset. Would you buy it at current price? If no, sell.
Mental accounting
Treating money differently based on its “source” or “label” rather than fungibility.
Manifestations
- Windfall money gets spent. €2,000 bonus goes to extravagant purchase; €2,000 of savings for rent doesn’t.
- “Investment” money vs “emergency” money. Keeping emergency fund at 0% in conto corrente instead of earning 3% elsewhere, because it’s “emergency money” and shouldn’t be “at risk.”
- Debt coexisting with savings. Carrying a €3,000 credit card balance at 20% while keeping €10,000 in savings at 2%. Irrational — pay off debt first.
Defense
- Money is fungible. Every euro is the same. Treat your whole financial picture as one.
- Debt reduction before savings when interest rates on debt exceed savings rates.
Present bias
Over-weighting immediate outcomes vs future.
Manifestations
- Undersaving for retirement. “I’ll save more later.” Later never comes.
- Short-term trading. Chasing quick gains instead of long-term holding.
- Consumer debt. Buying something now even when rational to wait or save.
Defense
- Automate savings. Remove the need for repeated willpower.
- Visualize future self. People save more when they see age-progressed photos of themselves.
- Pre-commitment. Contractual savings (fondo pensione locked until retirement) prevents present-biased decisions.
The gender gap in behavioral finance
Academic research (Barber and Odean) finds men trade 45% more than women in retail brokerage accounts, and their performance is 1-2% per year worse as a result.
Main difference: overconfidence. Men tend to overestimate their stock-picking ability. Women trade less, hold longer, and capture more of market returns.
Not a universal rule, but a useful corrective: if you feel “particularly confident” about a stock pick, that confidence itself is a warning sign.
The “panic gap”
Dalbar’s annual “Quantitative Analysis of Investor Behavior” study consistently shows retail investors underperforming the funds they hold by ~2-3% per year.
Why? Because they buy funds after they’ve gone up (FOMO) and sell after they’ve gone down (fear). They’re not doing what the fund manager does; they’re jumping in and out of funds at worst times.
Over 20-year windows, this “behavior gap” costs retail investors roughly 40-60% of potential returns.
Defenses that work
Putting it all together. Research (from Richard Thaler, Brigitte Madrian, Shlomo Benartzi) on what actually helps:
- Automation. PAC, auto-invest, auto-pay. Remove decisions.
- Pre-commitment. Lock into a plan before stress hits. Fondo pensione, recurring transfers.
- Default settings. Make good behavior the default, bad behavior the override.
- Time pressure defusion. Sleep on decisions. Any urgency to “decide now” is almost always fake.
- Small periodic reviews. Monthly brief review; avoid obsessive checking.
- Accountability partners. Discuss major decisions with a trusted friend or advisor.
What to do with this lesson
Three things:
- Name your biases. Which of the above resonate most strongly? Those are the ones to watch.
- Automate what you can. PAC, auto-transfers, auto-rebalance. Remove biased decision moments.
- Don’t act on feelings in market hours. If you feel urgency to sell/buy, sleep on it. Re-evaluate tomorrow.
Sources
- Daniel Kahneman — Thinking, Fast and Slow, 2011.
- Richard Thaler, Cass Sunstein — Nudge, 2008.
- Barber, Odean — Boys Will Be Boys, Quarterly Journal of Economics, 2001.
- Dalbar — Quantitative Analysis of Investor Behavior. Annual.
- Morgan Housel — The Psychology of Money, 2020.
Next lesson: time in the market beats timing the market (rewrite of existing post) — missing the 10 best days, Italian market 1998-2024 data.