행동 경제학: 투자자가 진정한 부를 구축하지 못하게 만드는 숨겨진 장벽들

February 2026 Financial Insights Newsletter / February 10, 2026

By Genti Cici, CFP®, CAIA / W/Dr. TaiYoung Lee

Behavioral Finance: The Hidden Barriers Keeping Investors from Building Real Wealth

Most investors underperform the markets not because of poor information or bad luck, but because of predictable psychological patterns that override rational decision-making. These behavioral biases rooted in human emotion and cognition create the largest gaps between market returns and what people actually achieve in their portfolios.

Drawing from advisor surveys, DALBAR's long-term studies on investor behavior, academic meta-analyses, and foundational work by Tversky & Kahneman (2002 Nobel Prize Winner on Behavioral Economics), the following list ranks the most prevalent mistakes from highest to lowest impact. Loss aversion consistently emerges as the dominant force, with losses registered roughly twice as strongly as equivalent gains, leading to costly holding patterns and premature sales.

Here are the top behavioral finance mistakes, expressed in the first-person voice many investors use to rationalize their choices, if they were honest to themselves:

1. I want to keep the losers (as they’ll come back) but sell the winners early even if a small gain (disposition effect / loss aversion) This remains the single most common and damaging bias. Advisors report it as the top client error, and it accounts for a significant portion of the persistent underperformance gap documented in DALBAR analyses.

   
   

2. I overestimate my knowledge or ability to predict outcomes and trade too much (overconfidence bias) Overconfidence drives excessive trading, unnecessary risk-taking, and chronic under-diversification. Empirical evidence shows it affects both retail investors and, at times, professionals, leading to higher costs and lower net returns.

   
   

3. I chase recent performance or hot trends without regard for fundamentals (recency bias) In an era of constant news and social media, recency bias ranks near the top in advisor observations. It fuels momentum chasing, poor entry/exit timing, and amplified volatility exposure.

   
   

4. I want my investments to work now or very soon, or I’ll bail on them (short-term thinking / myopia / present bias) Emotional impatience compounds recency effects, prompting reactive selling during temporary drawdowns and undermining long-term compounding.

   
   

5. I want to make a lot of money by following what has made a lot of money recently (herd following / momentum chasing) Herding appears frequently during bubbles and corrections, generating collective euphoria or panic that distorts rational pricing.

   
   

6. I know I’m right in my opinion and will selectively only read articles that validate my thoughts and make me feel right (confirmation bias) In information-saturated environments, confirmation bias reinforces existing views, filters out disconfirming evidence, and perpetuates other errors.

   
   

7. I want to put most or all of the money in few stocks, since I know they’ll definitely be winners (due to … [insert your strong opinion]) (not diversifying / concentration risk) Concentration often stems from overconfidence or familiarity, increasing portfolio volatility and the potential for severe drawdowns among self-directed investors.

   
   

8. I know this stock will come back since at one point it was at this [insert very high price it was once] price (anchoring bias) Anchoring to past highs slows adaptation to new information and sustains misjudgments long after fundamentals have shifted.

   
   

9. I just want to make money, regardless of a plan or what the money is for (not having a plan / lack of disciplined strategy) Without a clear, written investment policy tied to personal goals and risk tolerance, other biases operate unchecked. This absence of structure is widespread and acts as an amplifier rather than a standalone driver.

   
   

Awareness of these patterns is the first step toward better outcomes. The most effective countermeasures include:

• Establishing a written investment policy statement upfront.

• Implementing rules-based rebalancing and systematic reviews.

• Limiting exposure to short-term noise (e.g., reducing daily market checks).

• Seeking objective accountability, whether through an advisor or structured self-review processes.

  
  

Behavioral finance teaches us that discipline and process outperform emotion and intuition over time. Protecting against these mistakes is often more valuable than chasing the next great idea. Often these behavioral mistakes cost 3-4% or more in reduced returns every year, and often, during times of panic or euphoria the cost is much higher.

If any of these resonate with your own experience, or if you would like to discuss how they may be influencing your portfolio, I welcome the conversation on how to reduce them together.

Sincerely,

Genti Cici, CFP^® / W. Dr. Tai Young Lee