21 cards · Stock Market & Investing · answer each one, then read the explanation. Your score tallies below. Looking for Behavioral finance bias pairs investors mix up, side by side? Read the explainer.
An investor bought a stock at $80 per share. It has since fallen to $50. Despite the company's fundamentals deteriorating with no sign of recovery, the investor refuses to sell, saying 'I'll sell when it gets back to what I paid.' Which behavioral bias does this most clearly illustrate?
AHerding — the investor is following what other shareholders are doing by holding the stock
BConfirmation bias — the investor is only seeking information that confirms the stock will recover, while ignoring evidence of continued decline
CAnchoring bias — the investor is fixated on the purchase price as a reference point, treating it as the stock's 'true' value even though that price is irrelevant to the stock's current prospects and future trajectory
DOverconfidence bias — the investor believes they can time the market perfectly and sell at the exact moment the price recovers
Correct answer: .
This is a textbook case of anchoring: the investor has anchored their decision to the purchase price of $80, treating it as a psychologically significant threshold despite it carrying no information about the stock's future value. Rational analysis would evaluate whether to hold or sell based on current fundamentals and forward-looking prospects, not the sunk cost of entry. Confirmation bias would apply if the scenario described the investor seeking only bullish news, but the scenario focuses on the price anchor. Herding describes following the crowd, which isn't what's happening here — the investor is making an individual decision. Overconfidence would apply if the investor expressed certainty about predicting price movements, but the core behavior described is attachment to a reference point.
Source: Kahneman, D. & Tversky, A. (1979), 'Prospect Theory'; CFA Institute, Behavioral Finance
A retail investor looks at their brokerage account and notices that three of their holdings are up significantly while two are down. They sell the three winners to 'lock in gains' but hold the two losers, hoping they recover. This pattern of selling winners too early and holding losers too long is known as what?
AMean reversion trading — a rational strategy based on the statistical tendency of asset prices to return to their long-run average
BThe disposition effect — the tendency for investors to sell assets that have increased in value while keeping assets that have declined in value, driven by loss aversion and the desire to avoid realising a loss
CMomentum investing — buying recent winners and selling recent losers to capture trending price movements
DTax-loss harvesting — strategically selling losers to offset capital gains and reduce tax liability
Correct answer: .
The disposition effect, identified by Shefrin and Statman (1985), describes investors' tendency to sell winners prematurely while holding losers too long. It is driven by prospect theory: realising a gain provides a certainty of profit (which feels good), while selling a loser makes the loss feel permanent and painful. The option calling it mean reversion trading would imply a rational expectation that losers will recover — but the disposition effect is a bias, not a strategy, and often leads to worse returns. The option describing momentum investing is the opposite behavior: momentum investors would sell losers and hold winners. Tax-loss harvesting would mean selling the losers for a tax benefit, which is also the opposite of what this investor does.
Source: Shefrin, H. & Statman, M. (1985), 'The Disposition to Sell Winners Too Early and Ride Losers Too Long'; CFA Institute, Behavioral Finance
During a market bubble, an investor notices that nearly everyone in their social circle is buying a particular asset class, and media coverage is overwhelmingly positive. The investor decides to invest heavily despite having no independent analysis. Which cognitive bias or social influence is most directly at work?
AFraming effect — the investor's decision is influenced by the way information about the asset class is presented in the media rather than the underlying facts
BRecency bias — the investor is giving excessive weight to the most recent price performance and assuming that recent trends will continue indefinitely
CSurvivorship bias — the investor only hears success stories from people who profited and never hears about those who lost money on the same asset class
DHerding behavior — the investor is following the actions of the crowd rather than conducting independent analysis, driven by the assumption that a large group of people cannot all be wrong
Correct answer: .
Herding is the tendency to follow the crowd's investment decisions rather than making independent assessments. During bubbles, herding amplifies price movements as more participants pile in, each reasoning that so many people cannot be wrong. The scenario specifically describes the investor following social-circle behavior and positive media buzz without doing their own analysis, which is the defining feature of herding. Recency bias would apply if the investor were primarily focused on recent returns; while related, the trigger here is social influence, not recent performance alone. Survivorship bias is real but is not the primary driver described — the investor is responding to live social pressure, not just hearing filtered stories. Framing effect relates to how choices are presented, which is a secondary factor here compared to the dominant herd dynamic.
Source: CFA Institute, Behavioral Finance; Banerjee, A. (1992), 'A Simple Model of Herd Behavior'
A study of retail brokerage accounts found that investors who traded the most frequently earned significantly lower net annual returns than investors who traded the least frequently, even though the two groups' gross stock-picking performance was similar before costs. Which behavioral bias best explains why the highest-frequency traders, believing their own information and analysis to be more reliable than it actually was, ended up underperforming after transaction costs?
AOverconfidence bias — investors overestimate the precision of their own information and analytical skill, leading them to trade far more often than a realistic assessment of their edge would justify, with the resulting transaction costs eroding returns
BHerding — the investors are simply copying the trading decisions of other market participants around them
CAnchoring bias — the investors are fixated on a past purchase price and refusing to adjust their view
DThe disposition effect — the investors are selling their winning positions too early while holding onto their losing positions
Correct answer: .
This describes the well-documented finding of Barber and Odean's research on individual investor trading (published as 'Trading Is Hazardous to Your Wealth' in the Journal of Finance), which found that the households who traded most actively earned meaningfully lower net returns than those who traded least, despite similar raw stock-picking ability. The gap is explained by overconfidence: investors overestimate the precision and edge of their own analysis, which leads them to trade far more than a rational assessment of their actual skill would justify, and the resulting commissions, spreads, and taxes eat into returns. Herding is wrong because it describes correlated behavior driven by following the crowd, not an individual's excessive personal trading frequency. Anchoring bias is wrong because it concerns fixation on an irrelevant reference price, not a belief in one's own analytical superiority. The disposition effect is wrong because it describes which specific positions get sold (winners) versus held (losers), not the overall frequency of trading activity.
Source: Barber, B. & Odean, T. (2000), 'Trading Is Hazardous to Your Wealth', Journal of Finance; CFA Institute, Behavioral Finance
Before adding to a stock position, an investor exclusively reads bullish analyst reports and enthusiastic online message-board posts about the company, while skipping or dismissing the bearish reports that appeared in the very same search results. Which cognitive bias does this selective information-gathering pattern most directly illustrate?
ARecency bias — giving excessive weight to the most recent price trend when deciding whether to add to the position
BThe framing effect — being swayed by how the same underlying facts about the company happen to be presented
CConfirmation bias — seeking out and giving disproportionate weight to information that supports a belief already held, while ignoring or discounting available disconfirming evidence
DSurvivorship bias — only being exposed to a dataset that has already filtered out the failures
Correct answer: .
Confirmation bias is the tendency to seek out, notice, and give disproportionate weight to information that confirms a belief someone already holds, while ignoring, dismissing, or under-weighting equally available evidence that contradicts it. Here the investor already leans bullish and then deliberately curates their reading to reinforce that view, even though bearish reports were sitting in the same search results. Recency bias is wrong because it describes over-weighting the most recent price performance when forming expectations, not selectively filtering which sources of information to read. The framing effect is wrong because it concerns how identical facts are presented (for example as a gain versus a loss) changing a decision, not a deliberate choice to avoid an entire category of sources. Survivorship bias is wrong because it describes a systematic gap in a dataset itself (such as failed funds being excluded from a database), not an individual's personal selective reading habits.
Source: CFA Institute, Behavioral Finance; Nickerson, R.S. (1998), 'Confirmation Bias: A Ubiquitous Phenomenon in Many Guises', Review of General Psychology
An investor receives an unexpected $10,000 year-end bonus and mentally labels it 'house money,' investing all of it in speculative penny stocks she would never consider for her regular retirement savings, which she keeps in a conservative index fund. Which concept describes this tendency to treat money differently based on its source or mental label, rather than treating all money as equally fungible?
ALoss aversion — losses are weighted more heavily than equivalent gains in the investor's decision-making
BMental accounting — investors create separate mental 'buckets' for money based on its source or intended use and apply different risk rules to each bucket, even though money is fungible
CThe endowment effect — an asset is valued more highly simply because the investor already owns it
DRegret aversion — avoiding an action specifically to sidestep the pain of a future regret
Correct answer: .
Mental accounting, a concept developed by Richard Thaler, describes how people create separate mental 'accounts' for money depending on its source, intended purpose, or how it was labeled, and then apply different risk tolerances or spending rules to each account, even though a dollar is a dollar regardless of where it came from. Here the investor treats the bonus as low-stakes 'house money' suitable for speculation while treating her regular savings as money that must be protected, despite both being part of the same total wealth. Loss aversion is wrong because it describes an asymmetry in how losses versus equivalent gains are weighted emotionally, not a tendency to sort money into separate buckets by origin. The endowment effect is wrong because it concerns overvaluing a specific asset merely because it is already owned, not treating cash differently based on its label. Regret aversion is wrong because it describes avoiding decisions to prevent anticipated future regret, which is a different mechanism from source-based mental labeling of funds.
Source: Thaler, R. (1985), 'Mental Accounting and Consumer Choice', Marketing Science; CFA Institute, Behavioral Finance
An investor is offered a single coin-flip bet: heads, they win $150; tails, they lose $100. Despite the bet's positive expected value of $25, the investor declines, explaining that the possibility of losing $100 feels far worse than the equivalent chance of winning $150 feels good. Which concept from prospect theory does this best illustrate?
AThe disposition effect — a tendency to sell winning positions too early while holding losing positions too long
BAnchoring bias — fixation on an irrelevant reference number when evaluating a decision
CRegret aversion — avoiding an action specifically because of the anticipated regret if it turns out badly
DLoss aversion — under prospect theory, losses are weighted roughly twice as heavily in a person's subjective value function as equivalent-sized gains, so a bet with positive expected monetary value can still feel unattractive
Correct answer: .
Loss aversion, a core finding of Kahneman and Tversky's prospect theory, holds that losses are subjectively weighted roughly two to two-and-a-half times as heavily as equivalent-sized gains. This is why a bet with a clearly positive expected value in raw dollar terms, like winning $150 versus losing $100 on a fair coin flip, can still feel unattractive: the pain of the potential $100 loss looms larger in the decision than the pleasure of the potential $150 gain. The disposition effect is wrong because it describes selling behavior on positions an investor already holds, not a reaction to a new hypothetical bet. Anchoring bias is wrong because it concerns fixating on an unrelated reference point, which isn't present in this scenario. Regret aversion is wrong because it concerns avoiding an action due to the anticipated feeling of regret over a bad outcome relative to the path not taken, a related but distinct mechanism from the raw asymmetric weighting of gains and losses described here.
Source: Kahneman, D. & Tversky, A. (1979), 'Prospect Theory: An Analysis of Decision under Risk', Econometrica; CFA Institute, Behavioral Finance
A US-based investor holds a retirement portfolio that is 90% invested in US stocks, even though the US represents roughly 60% of global stock market capitalization, and she has never seriously considered adding international equity exposure, saying she 'understands US companies better.' Which behavioral tendency does this portfolio construction most directly illustrate?
AHome bias — investors systematically overweight domestic or otherwise familiar securities relative to their share of the global market, often out of comfort with the familiar rather than a reasoned diversification decision
BHerding — following the investment decisions of the crowd rather than making an independent assessment
CMental accounting — treating money differently depending on its source or intended use
DOverconfidence bias — overestimating the precision of one's own trading and analytical skill broadly
Correct answer: .
Home bias describes the well-documented tendency for investors to overweight domestic (or otherwise familiar) securities well beyond what their share of the global investable market would justify, typically driven by comfort with the familiar rather than a deliberate diversification decision. Here the investor holds far more in US stocks than the US's roughly 60% share of global market capitalization would suggest, and her stated reason is familiarity rather than analysis, which is the defining feature of home bias. Herding is wrong because it describes following what other market participants are currently doing, not a standing geographic concentration built on personal comfort. Mental accounting is wrong because it concerns sorting money into separate buckets by source or label, not concentrating holdings by geography. Overconfidence bias is wrong because it more broadly describes overestimating one's analytical or trading skill (often shown through excessive trading), whereas this scenario is specifically about a persistent geographic concentration driven by familiarity, which is the more precise term.
Source: French, K. & Poterba, J. (1991), 'Investor Diversification and International Equity Markets', American Economic Review; CFA Institute, Behavioral Finance
After a company's stock unexpectedly doubled following a surprise product announcement, an investor who did not own the stock beforehand tells colleagues, 'I knew that was going to happen,' even though before the announcement she had expressed no such prediction and the announcement itself was not publicly anticipated. Which bias does this after-the-fact certainty illustrate?
AThe gambler's fallacy — believing that an outcome is 'due' after a run of a different outcome
BThe availability heuristic — overestimating the probability of an event because vivid examples of it come easily to mind
CHindsight bias — after learning an outcome, people tend to overestimate how predictable that outcome was beforehand, reconstructing their prior beliefs as more confident than they actually were
DConfirmation bias — seeking out information that supports a belief already held while ignoring contradictory evidence
Correct answer: .
Hindsight bias, sometimes described as 'creeping determinism,' is the tendency for people to overestimate, after an outcome is known, how predictable that outcome actually was beforehand. Here the investor retroactively reconstructs a confident prediction she never actually made or expressed, because the surprising announcement's outcome now feels obvious in hindsight; this matters for investors because it can breed unwarranted overconfidence in future forecasting ability. The gambler's fallacy is wrong because it concerns misjudging the probability of an upcoming independent event based on a recent streak, not reconstructing a past belief. The availability heuristic is wrong because it concerns overestimating the probability of an event because vivid or memorable examples come easily to mind when estimating frequency, not the retroactive sense that a specific past event was predictable. Confirmation bias is wrong because it concerns selectively seeking information that supports a currently held belief, not retroactively rewriting what one's belief was before an event occurred.
Source: Fischhoff, B. (1975), 'Hindsight is not equal to foresight', Journal of Experimental Psychology; CFA Institute, Behavioral Finance
After three consecutive years of 25%-plus annual returns in a particular sector fund, an investor raises her expected long-run annual return assumption for that sector to match those recent results and shifts new contributions heavily toward it, reasoning that 'this is clearly what the sector does now.' Which bias most directly describes over-weighting the most recent years' performance when forming expectations about long-run future returns?
AHerding — following what other investors are currently doing in the market
BThe gambler's fallacy — expecting a reversal simply because of a recent streak
CHindsight bias — reconstructing a past belief as more confident than it actually was after an outcome is known
DRecency bias — giving disproportionate weight to recent events and performance when forming expectations about the future, extrapolating a short recent trend as if it represents a durable long-run pattern
Correct answer: .
Recency bias is the tendency to give disproportionate weight to recent events and performance when forming expectations about the future, effectively extrapolating a short recent trend forward as if it represents a durable long-run pattern. Here the investor takes just three years of unusually strong returns and revises her long-run return assumption to match, even though a handful of years says little about a sector's true long-run average, and shifts new money accordingly. Herding is wrong because it describes following the current actions of other market participants, not an investor's own extrapolation from her own portfolio's recent performance. The gambler's fallacy is wrong because it describes the opposite reasoning: expecting a reversal after a streak rather than expecting the streak to continue. Hindsight bias is wrong because it concerns retroactively viewing a past outcome as having been predictable, not projecting a recent trend forward into expectations about the future.
Source: CFA Institute, Behavioral Finance; Barberis, N. & Thaler, R. (2003), 'A Survey of Behavioral Finance', Handbook of the Economics of Finance
Shortly after extensive media coverage of a sudden, sharp market crash, an investor becomes convinced that a similarly severe crash is highly likely within the next few months, and shifts a large portion of her portfolio to cash, even though the historical base-rate frequency of such crashes has not actually changed. Which cognitive shortcut best explains this investor's overestimate of the crash's probability?
ALoss aversion — weighting a loss more heavily than an equivalent-sized gain once it has already been experienced
BThe availability heuristic — people estimate the probability of an event based on how easily examples of it come to mind, and a vivid, heavily covered recent event becomes mentally more 'available,' causing its perceived likelihood to be overestimated relative to its actual base-rate frequency
CMental accounting — treating money differently depending on its source or intended use
DHome bias — overweighting domestic or otherwise familiar securities relative to their share of the global market
Correct answer: .
The availability heuristic, identified by Tversky and Kahneman, describes how people estimate the probability or frequency of an event based on how easily examples of it come to mind rather than on its actual statistical base rate. A recent, vivid, heavily covered market crash is highly 'available' in memory, which causes the investor to overestimate how likely a similarly severe crash is in the near future, even though the underlying base-rate frequency of such events has not changed. Loss aversion is wrong because it concerns the asymmetric emotional weighting of an already-realized or contemplated loss versus an equivalent gain, not a probability-estimation shortcut driven by how memorable an event is. Mental accounting is wrong because it concerns sorting money into separate mental buckets by source or label, unrelated to estimating the likelihood of a future market event. Home bias is wrong because it concerns a standing geographic or familiarity-driven concentration in holdings, not a shift in perceived crash probability driven by recent vivid news coverage.
Source: Tversky, A. & Kahneman, D. (1973), 'Availability: A Heuristic for Judging Frequency and Probability', Cognitive Psychology; CFA Institute, Behavioral Finance
A stock has risen for five consecutive trading days. An investor concludes that a decline 'is due' purely because of this streak, and sells the position expecting a reversal, even though daily price movements in this stock have historically shown no meaningful serial correlation. Which reasoning error does this most directly illustrate?
AThe gambler's fallacy — the mistaken belief that after a run of one outcome, the opposite outcome becomes more likely on the next independent trial, even when the underlying events are actually independent
BRecency bias — extrapolating a recent trend forward as if it will continue indefinitely
CLoss aversion — weighting a potential loss more heavily than an equivalent-sized potential gain
DThe disposition effect — selling winning positions too early while holding losing positions too long
Correct answer: .
The gambler's fallacy is the mistaken belief that after a run of one outcome, the opposite outcome becomes more likely on the next independent trial, as if random or near-random events must 'balance out.' Here the investor treats five consecutive up days as making a decline more likely, even though the stock's daily moves have shown no meaningful serial correlation historically, meaning each day's move is effectively independent of the recent streak. Recency bias is wrong because it describes the opposite reasoning: extrapolating a recent trend forward as likely to continue, rather than expecting it to reverse. Loss aversion is wrong because it concerns the asymmetric emotional weighting of losses versus gains, not a probability judgment about the next price move. The disposition effect is wrong because it describes a pattern of selling winners and holding losers based on an investor's own accumulated gain or loss on a position, not a belief that a price streak makes a reversal statistically due.
Source: Tversky, A. & Kahneman, D. (1971), 'Belief in the Law of Small Numbers', Psychological Bulletin; CFA Institute, Behavioral Finance
An investor inherits 500 shares of a company's stock. When asked whether she would buy those same shares today at their current market price if she did not already own them, she says no, she considers the company overvalued. Yet she has no plans to sell her inherited shares and would demand a price well above the current market price to part with them. Which bias does this gap between her willingness to accept and her willingness to pay most directly reflect?
AMental accounting — treating money differently depending on its source or intended use
BConfirmation bias — seeking out information that supports a belief already held
CHindsight bias — reconstructing a past belief as more confident than it actually was
DThe endowment effect — people tend to assign a higher value to an asset simply because they own it, demanding more to give it up than they would be willing to pay to acquire the identical asset from scratch
Correct answer: .
The endowment effect, demonstrated experimentally by Kahneman, Knetsch, and Thaler, describes how people tend to assign a higher value to an asset simply because they already own it, which produces a systematic gap between the minimum price they would accept to sell it (higher) and the maximum price they would pay to acquire the identical asset if they didn't already hold it (lower). Here the investor's willingness-to-accept for her inherited shares is well above her willingness-to-pay for the same shares, and objectively she even believes the company is overvalued at the current price, yet ownership alone inflates the value she assigns to holding on. Mental accounting is wrong because it concerns sorting money into separate buckets based on source or label, not an ownership-driven valuation gap for a single held asset. Confirmation bias is wrong because it concerns selectively seeking supportive information, not a discrepancy between buying and selling prices. Hindsight bias is wrong because it concerns retroactively viewing a past outcome as having been predictable, which is unrelated to a current valuation gap based on ownership.
Source: Kahneman, D., Knetsch, J. & Thaler, R. (1990), 'Experimental Tests of the Endowment Effect and the Coase Theorem', Journal of Political Economy; CFA Institute, Behavioral Finance
Two financial advisors are each presenting the same bond fund's historical performance to a prospective client. The first advisor says, '92% of comparable funds avoided any loss over a rolling five-year period.' The second advisor, describing the identical underlying data, says, '8% of comparable funds suffered a loss over some rolling five-year period.' Even though the two statements are mathematically equivalent, the client reacts far more favorably to the first advisor's description. Which bias does this difference in reaction most directly illustrate?
AThe framing effect — presenting mathematically identical information in terms of a positive outcome (avoiding a loss) produces a more favorable reaction than presenting the same information in terms of a negative outcome (suffering a loss)
BConfirmation bias — seeking out and giving extra weight to information that supports a belief already held, while discounting information that contradicts it
CRecency bias — giving disproportionate weight to the most recent data point when forming an overall judgment about a trend
DHindsight bias — reconstructing a past belief as though an outcome had been predictable all along, after the outcome is already known
Correct answer: .
The framing effect, a core finding of prospect theory, describes how the same underlying facts can produce different reactions depending purely on how they are worded — presenting a statistic in terms of a gain or success (avoiding a loss) is received more favorably than presenting the mathematically identical statistic in terms of a loss or failure (suffering a loss), even though a fully rational decision-maker should react identically to equivalent information. Here both advisors describe the exact same five-year loss data, yet the client's reaction swings with the wording alone. Describing a belief already held as being reinforced by selectively sought information does not fit, since the client has not been shown to be searching for or filtering information to confirm a prior view — the difference in reaction is driven entirely by phrasing, not selective evidence-gathering. Giving extra weight to the most recent data point when forming an overall judgment does not fit either, since both statements describe the same five-year window rather than emphasizing newer information over older information. Reconstructing a past belief as more confident or predictable after the fact also does not fit, since nothing here involves looking back on a prior prediction — the client is reacting to a live presentation of statistics, not revising a memory of an earlier belief.
Source: Tversky, A. & Kahneman, D. (1981), 'The Framing of Decisions and the Psychology of Choice', Science; CFA Institute, Behavioral Finance (framing bias)
An investor is evaluating a well-known company with an excellent reputation, a famous brand, and a widely admired management team. Reasoning that such an impressive company must also make for an attractive stock purchase, the investor buys shares without comparing the price paid to the company's earnings, cash flows, or any other valuation measure. Which bias does this reasoning most directly illustrate?
AHome bias — favoring investments in one's own country or in companies that feel familiar, over comparably attractive foreign or unfamiliar alternatives
BThe representativeness heuristic — judging an investment by how closely it resembles the mental prototype of a 'good company,' rather than by assessing the price paid relative to the company's underlying fundamentals
CIllusion of control — overestimating the degree to which personally selecting an investment increases one's control over its outcome
DHindsight bias — reconstructing a past belief as though an outcome had been predictable all along
Correct answer: .
The representativeness heuristic describes judging something by how closely it matches a mental stereotype or prototype, rather than by relevant statistical or financial evidence — here, the investor equates a company that resembles the prototype of 'a good company' (strong reputation, brand, management) with the prototype of 'a good stock to buy,' skipping any comparison of the price paid to earnings, cash flow, or other fundamentals. Research tying this exact error to the 'good company, good stock' mistake finds that a company's quality as a business is a poor predictor of its stock's forward return once price is ignored. Favoring familiar or domestically based companies over comparably attractive unfamiliar alternatives does not fit, since nothing here involves the company's geographic or cultural familiarity — the investor's error is about conflating business quality with investment attractiveness generally. Overestimating how much personally choosing an investment increases control over its outcome does not fit, since the investor is not shown believing that selecting the stock herself gives her more influence over how it performs. Reconstructing a past belief as more predictable in hindsight does not fit, since this scenario describes a decision being made in the present, not a recollection of an earlier prediction after an outcome is already known.
Source: Lakonishok, J., Shleifer, A. & Vishny, R.W. (1994), 'Contrarian Investment, Extrapolation, and Risk', Journal of Finance; CFA Institute, Behavioral Finance (representativeness heuristic)
An investor who picked three stocks in a row that each rose sharply credits her own superior analysis and stock-picking skill for every one of those gains. When two of her other stock picks previously fell sharply, she attributed those losses to 'bad luck' and 'unpredictable market conditions' rather than to any flaw in her own analysis. Which bias does this asymmetric pattern of explaining her own results most directly illustrate?
ASelf-attribution bias — crediting good outcomes to one's own skill and judgment, while attributing bad outcomes to external factors such as luck or circumstances beyond one's control
BOverconfidence bias — holding a general belief that one's own judgment, knowledge, or abilities are better calibrated than they objectively are
CHindsight bias — reconstructing a past belief as though an outcome had been predictable all along, once the outcome is already known
DIllusion of control — overestimating the degree to which personal involvement or choice can influence an outcome that is substantially governed by chance
Correct answer: .
Self-attribution bias is the specific, asymmetric pattern of explaining one's own results: successes are credited to personal skill and ability, while failures are explained away as the product of bad luck or external circumstances, rather than being attributed consistently to the same underlying cause regardless of outcome. That is exactly what this investor does — three gains become evidence of her skill, two losses become evidence of an unlucky market, with no self-consistent standard applied either way. A general belief that one's abilities are better than they objectively are describes overconfidence broadly, but the question tests the specific causal-attribution mechanism (success equals skill, failure equals luck) that research identifies as one of the processes that builds and reinforces overconfidence over time, not overconfidence itself. Reconstructing a past belief as more predictable after the fact does not fit, since the investor is not shown revising her memory of what she originally expected — she is explaining outcomes that have already occurred using inconsistent reasoning. Overestimating how much personal involvement increases control over a chance-driven outcome does not fit either, since nothing here involves a belief that her actions influenced whether the stocks rose or fell, only how she explains the results afterward.
Source: Gervais, S. & Odean, T. (2001), 'Learning to Be Overconfident', Review of Financial Studies; CFA Institute, Behavioral Finance (self-attribution bias)
An investor personally selects and actively manages every stock in her portfolio, picking individual shares with no particular informational advantage over any other market participant. She believes that because she handpicks and actively trades her own positions, she has more control over avoiding losses than an otherwise identical investor holding a passive index fund containing a similar, randomly assembled set of holdings. Which bias does this belief most directly illustrate?
AOverconfidence bias — a general belief that one's own judgment, knowledge, or abilities are better calibrated than they objectively are
BSelf-attribution bias — crediting good outcomes to one's own skill while attributing bad outcomes to external factors beyond one's control
CIllusion of control — overestimating the degree to which active personal involvement and choice can influence an outcome that is substantially governed by chance
DHome bias — favoring investments that feel familiar, such as domestic companies, over comparably attractive unfamiliar alternatives
Correct answer: .
The illusion of control, first documented experimentally by psychologist Ellen Langer, describes overestimating how much personal involvement, choice, or active participation can influence an outcome that is actually governed largely by chance. Here the investor believes that actively picking and trading her own stocks gives her more control over avoiding losses than passively holding an equivalent, randomly assembled set of the same kinds of holdings, even though she has no informational edge that would justify that belief — the outcome is driven by the market, not by the act of choosing. A general belief that one's abilities are better calibrated than they objectively are describes overconfidence broadly, which is related but distinct, since this scenario is specifically about believing that active choice itself confers control, not about overrating the accuracy of one's analysis. Crediting good outcomes to skill while blaming bad outcomes on luck does not fit, since the investor is not shown explaining past results at all — she is forming a belief about her degree of control going forward. Favoring investments that feel familiar over unfamiliar alternatives does not fit, since nothing here involves a preference based on geographic or cultural familiarity between different holdings.
Source: Langer, E.J. (1975), 'The Illusion of Control', Journal of Personality and Social Psychology; Barber, B.M. & Odean, T. (2000), 'Trading Is Hazardous to Your Wealth', Journal of Finance
A company automatically enrolls every new employee into its retirement savings plan at a default contribution rate and a default investment fund, requiring an employee to actively complete a form to select a different rate or fund. Years of data show that the overwhelming majority of employees remain at the exact default rate and fund indefinitely, even when it does not match their own stated retirement savings goals. Which bias best explains why the default option exerts such a strong pull, independent of whether it's actually the best choice for each employee?
ARegret aversion — avoiding an action because the anticipated regret from a bad outcome that resulted from actively choosing differently feels worse than the anticipated regret from an equally bad outcome that resulted from doing nothing
BStatus quo bias — a strong preference for keeping an existing arrangement unchanged, which causes a default option to be retained simply because changing it requires an active decision
CThe endowment effect — assigning a higher value to something simply because one already owns or holds it
DHerding — following the actions of a larger group rather than relying on independent analysis
Correct answer: .
Status quo bias describes a strong, general preference for leaving an existing arrangement unchanged, which causes a default option to persist simply because switching away from it requires an active decision, independent of whether the default is actually well suited to the individual. Research on retirement plans that moved from opt-in to automatic enrollment found that savings behavior changed dramatically even though the plan's underlying economic terms did not, showing that the default itself, not its merits, is what employees overwhelmingly stick with. Avoiding an action because of the anticipated emotional sting of an active choice turning out badly does not fit as the best explanation here, since the scenario describes employees simply never acting at all rather than weighing the feared regret of a specific active switch going wrong — that emotional, action-versus-inaction asymmetry is a related but separate bias. Assigning extra value to something merely because it is already owned does not fit, since a default contribution rate or fund is not something an employee has taken ownership of through a deliberate acquisition — it was simply left unchanged. Following a larger group's actions does not fit either, since nothing here involves employees observing or copying what other people are doing; each employee simply fails to act on their own account.
Source: Samuelson, W. & Zeckhauser, R. (1988), 'Status Quo Bias in Decision Making', Journal of Risk and Uncertainty; Madrian, B.C. & Shea, D.F. (2001), 'The Power of Suggestion: Inertia in 401(k) Participation and Savings Behavior', Quarterly Journal of Economics
An investor has held a mutual fund that has underperformed its benchmark for two consecutive years. A colleague recommends switching to a different fund with a stronger recent track record. The investor decides to keep her money in the underperforming fund, explaining that if she switches and the new fund then performs worse, she would feel far more at fault and upset than if she simply stays put and the current fund continues to lag. Which bias is most directly reflected in this reasoning?
AStatus quo bias — a general preference for leaving an existing arrangement unchanged because switching requires an active decision, regardless of any anticipated emotional consequences
BThe disposition effect — selling winning positions too early to lock in gains while holding on to losing positions too long, hoping they recover
CLoss aversion — under prospect theory, losses are weighted roughly twice as heavily in a person's subjective value function as equivalent-sized gains
DRegret aversion — avoiding an action because the anticipated regret from a bad outcome that results from one's own active choice feels more painful than the anticipated regret from an equally bad outcome that results from doing nothing
Correct answer: .
Regret aversion describes an asymmetry in anticipated emotion: a bad outcome that follows from one's own deliberate, active choice is expected to feel more painful and more personally blameworthy than an equally bad outcome that follows from simply doing nothing, even when the two outcomes are financially identical. That is exactly the investor's stated reasoning — she isn't weighing expected returns, she is weighing how much worse she would feel if a new fund she actively chose underperformed, compared to the current fund continuing to lag on its own. A general preference for leaving an arrangement unchanged because switching requires effort does not fit as precisely, since the investor's own explanation is explicitly about anticipated feelings of fault and regret from an active choice, not about the inconvenience or friction of making a change. Selling winners early and holding losers too long does not fit, since the investor is not shown realizing any gains or losses on a specific position by selling it — she is choosing whether to switch funds entirely. Weighting losses roughly twice as heavily as equivalent gains describes the general magnitude asymmetry between gains and losses, which is related but distinct from this scenario's specific action-versus-inaction asymmetry in anticipated regret.
Source: CFA Institute, Behavioral Finance curriculum (regret-aversion bias); Shefrin, H. (2000), Beyond Greed and Fear, Harvard Business School Press
A company reports quarterly earnings that are far better than analysts had expected. Despite this clearly positive surprise, the stock's price does not immediately reprice to reflect the full extent of the good news; instead, it drifts upward gradually over the following several weeks, as analysts and investors slowly and incrementally revise their fundamental estimates for the company rather than fully incorporating the new information right away. Which bias best explains this slow, incomplete adjustment to new information?
AConservatism bias — updating prior beliefs too slowly and incompletely in response to new information, so that a price or forecast moves toward the new information gradually rather than all at once
BRecency bias — giving disproportionate weight to the most recent years of performance when forming expectations about long-run future returns
CAnchoring bias — fixating on an initial reference number and adjusting insufficiently away from it when evaluating new information
DOverreaction bias — reacting too strongly to a sustained run of news, pushing a price further from fundamental value than is warranted
Correct answer: .
Conservatism bias describes updating one's prior beliefs too slowly and incompletely when new information arrives, so that a price or a forecast converges toward what the new information actually implies only gradually, over an extended period, rather than adjusting immediately and fully. The earnings-surprise scenario here is a textbook case: a well-known model of investor sentiment built on exactly this mechanism shows that underreaction of this kind, where prices drift in the direction of a surprise for weeks or months afterward, is consistent with analysts and investors anchoring too heavily on their prior fundamental view and incorporating new evidence only partially at a time. Giving disproportionate weight to the most recent years of performance when forming long-run return expectations describes a different error about which historical data gets weighted in a forecast, not about how quickly a single piece of new information gets incorporated into current beliefs. Fixating on an initial reference number describes a related but distinct mechanism about insufficient adjustment away from a starting value during estimation, rather than the gradual, multi-week repricing process described here. Reacting too strongly to news and overshooting fundamental value describes the opposite pattern from what's shown — this scenario is explicitly an underreaction that takes weeks to catch up, not an excessive, overshooting response.
Source: Barberis, N., Shleifer, A. & Vishny, R. (1998), 'A Model of Investor Sentiment', Journal of Financial Economics; CFA Institute, Behavioral Finance (conservatism bias)
Researchers divided a large sample of exchange-listed stocks into a 'losers' portfolio of the worst-performing stocks over the prior three years and a 'winners' portfolio of the best-performing stocks over that same period. Over the following several years, the losers portfolio significantly outperformed the winners portfolio on average. One proposed explanation is that investors had pushed the losers' prices down too far, and the winners' prices up too far, relative to the companies' fundamentals during the initial three-year period. Which behavioral explanation does this reversal pattern most directly illustrate?
AThe gambler's fallacy — believing that an outcome is 'due' to reverse after a run of results, even when the underlying process has no real memory of past outcomes
BRecency bias — giving disproportionate weight to the most recent trend when forming expectations about what will happen next
COverreaction bias — investors react too strongly to a sustained run of bad or good news, pushing prices further from fundamental value than is warranted, a move that later partly reverses as the overreaction corrects
DConservatism bias — updating prior beliefs too slowly and incompletely in response to new information
Correct answer: .
Overreaction bias, identified in a landmark study that formed portfolios of past extreme winners and losers, describes investors reacting too strongly to a sustained run of good or bad news about a company, pushing its price further from what its fundamentals justify than is warranted; because the initial move overshoots, it tends to partly reverse over the following years as the mispricing corrects, producing exactly the pattern described here of prior losers beating prior winners afterward. Believing an outcome is 'due' to reverse after a run of results describes a fallacy about a single independent, memoryless random process, such as a coin flip or an individual stock's short-term price moves, not a documented, researched pattern of systematic mispricing and correction across a large portfolio of stocks tied to fundamentals. Giving disproportionate weight to the most recent trend when forming expectations describes extrapolating a trend forward, which would predict the winners continuing to win and the losers continuing to lose, the opposite of the reversal actually observed. Updating beliefs too slowly and incompletely in response to new information describes underreaction, which is the opposite mechanism from the overshooting, too-strong reaction described in this scenario.
Source: De Bondt, W.F.M. & Thaler, R. (1985), 'Does the Stock Market Overreact?', Journal of Finance; CFA Institute, Behavioral Finance (overreaction bias)
About Behavioral Finance & Investor Psychology
Classical finance theory assumes investors process information rationally and consistently prefer more expected return for less risk. Behavioral finance studies the systematic ways real investors depart from that assumption. Its foundational idea, prospect theory (Daniel Kahneman and Amos Tversky, 1979), found that losses loom larger than equivalent gains — people feel the pain of losing a given sum more intensely than the pleasure of gaining the same amount — a bias now called loss aversion, and one that shows up constantly in how investors actually trade.
Loss aversion's most-tested investing consequence is the disposition effect: the tendency to sell winning positions too early, to lock in a sure gain, while holding losing positions too long, hoping to avoid realizing the loss at all — the opposite of the "let winners run, cut losers" discipline most trading plans recommend. Other common biases include overconfidence (consistently overestimating one's own ability to pick winners or time the market, linked in research to excessive trading and lower realized returns), anchoring (fixating on an arbitrary reference point, like a stock's purchase price or 52-week high), and herding (following the crowd into or out of a position rather than independent analysis). The bias-pairs guide untangles loss aversion, the disposition effect, and several commonly confused neighbors.