CFA Level IPortfolio ManagementMedium

An investor keeps his retirement savings entirely in low-risk bonds, consistent with his stated low overall risk tolerance. Separately, he takes a $10,000 work bonus and invests it aggressively in speculative options, treating it as "house money" unrelated to his core portfolio. This behavior is best described as:

  1. AAnchoring bias
  2. BMental accounting
  3. CConfirmation bias
  4. DAvailability bias
Show answer & explanation

Correct answer: B. Mental accounting

Mental accounting is a behavioral bias in which investors treat money differently depending on its source or intended use, rather than viewing wealth holistically. Here, the investor segregates the bonus into a separate speculative "account" rather than integrating it into his overall risk profile, a classic example of mental accounting.

Why the other options are wrong

  • A. Anchoring relates to over-relying on an initial reference point, not compartmentalizing money.
  • C. Confirmation bias involves seeking information that supports existing beliefs, not compartmentalizing wealth.
  • D. Availability bias involves overweighting easily recalled information, not fund segregation.

Mental Accounting

A cognitive bias in which individuals separate money into distinct mental "buckets" based on source or purpose, rather than treating wealth as fungible.

  • Leads to inconsistent risk-taking across accounts
  • Common with windfalls treated as 'house money'
  • Can cause suboptimal overall portfolio risk management

Memory trick: Money is money — but mental accounting puts it in separate jars.

More Portfolio Management questions