Spencer Li

Self-Attribution Bias – Don’t Confuse Brains With a Bull Market!

Self-Attribution Bias in Trading: Why You Think You’re Better Than You Are

Last updated: 3 July 2026 · By Spencer Li, CFTe

Self-attribution bias is the tendency to credit your wins to your own skill while blaming your losses on bad luck, the broker, the platform, or the news. In trading it is dangerous for one simple reason: it quietly inflates how good you think you are. It comes in two flavours. Self-enhancing bias is claiming too much credit when a trade works. Self-protecting bias is denying responsibility when a trade fails. Both distort your scorecard in the same direction, upward. Left unchecked, the bias does two concrete kinds of damage: you stop learning from mistakes you refuse to see, and you drift into overconfidence, sizing up because you believe you have an edge you have not actually proven. The fix is not motivation or willpower. It is a record. Log every trade, win and loss, treat both objectively, and let the numbers grade you instead of your ego.

Here is how the bias works, why it fools good traders, and the one habit that beats it.

What is self-attribution bias?

Self-attribution bias (also called self-serving attributional bias) is the tendency to ascribe your successes to innate qualities like talent or foresight, while blaming your failures on outside influences like bad luck. It is one of the most common cognitive biases in behavioural finance, and trading is where it does the most quiet harm, because the feedback (your profit and loss) is delayed, noisy, and easy to misread.

There are two kinds, and it helps to keep them separate.

Self-enhancing bias is the propensity to claim an irrational degree of credit for your successes. If you intended to succeed and the outcome lined up with that intention, you perceive the result as proof your actions worked, regardless of whether your actions actually played any crucial role. The trade went your way, so your analysis must have been brilliant.

Self-protecting bias is the corollary, the irrational denial of responsibility for failure. When a trade goes wrong, you protect your self-esteem psychologically as you try to make sense of the loss. It was not your call that was bad. It was the broker, the platform, the surprise headline, the rigged market.

The two types, side by side

What it isThe story you tell yourselfThe damage
Self-enhancing biasOver-crediting your wins“I called that perfectly, I’m a good trader”Overconfidence, sizing up on an edge you never proved
Self-protecting biasDenying blame for your losses“Bad luck. The broker, the news, the platform”You never see the mistake, so you never learn from it

Notice that both biases bend the data the same way. One inflates the wins, the other deflates the responsibility for losses. Put together, they hand you a scorecard that says you are better than you are.

How it actually harms traders

This is not an abstract psychology problem. It impairs traders in two specific ways.

First, people who cannot perceive the mistakes they have made are, consequently, unable to learn from those mistakes. If every loss was someone else’s fault, there is nothing to fix. You repeat the same error for years and call it bad luck.

Second, traders who disproportionately credit themselves when good outcomes arrive become detrimentally overconfident in their own market savvy. That is the on-ramp to overconfidence bias, where you trade bigger and more often because you believe in an edge that the actual numbers do not support.

When trades turn out well, people like to think their method and analysis were fantastic, and that they are good traders. When trades do not turn out well, people blame their broker, their platform, the news, basically anything but themselves. Over time, this leads traders to think they are much better than they actually are.

What is the best solution for self-attribution bias?

The fix is not insight or affirmations. It is bookkeeping, done honestly.

Treat both winning and losing trades as objectively as possible. Tabulate and record them to build a running record. Then do an objective post-trade analysis, reviewing your records to learn from past mistakes, the real ones, in your own writing, before you had a chance to rewrite the story.

With enough data, you can analyse the consistency of your methods and returns honestly. The wins and losses sit in the same column, attributed the same way, and the pattern shows itself. As they say, the numbers do not lie.

This is exactly why my own trade journal is public, 404 trades with the losses left in. A public log is the cheapest cure for self-attribution bias I know, because you cannot quietly delete the trades that embarrass you.

Where the human edge comes in

A trading bot does not flatter itself. It does not remember a loss as bad luck and a win as genius. That neutrality is its advantage. Yours, as a human, is judgment, but judgment only compounds if it is honestly graded. A journal is how you borrow the machine’s objectivity. The discipline to log the ugly trade exactly as it happened, and to read your own record without spin, is the psychology and accountability edge, and it is one of the Five Edges no tool will keep for you.

FAQ

What is self-attribution bias in trading?
Self-attribution bias is the tendency to credit winning trades to your own skill while blaming losing trades on outside factors like bad luck, your broker, or the news. Over time it makes traders believe they are more skilled than their actual results show.

What are the two types of self-attribution bias?
The two types are self-enhancing bias (claiming too much credit for successes) and self-protecting bias (denying responsibility for failures). Both distort your self-assessment upward.

How does self-attribution bias lead to overconfidence?
When you over-credit yourself for wins, you start to believe you have a reliable edge. That belief leads you to trade bigger and more often, which is overconfidence bias, even when the underlying numbers do not support the confidence.

How do you overcome self-attribution bias as a trader?
Keep an objective trade record of every win and loss, then do a post-trade analysis reviewing those records. With enough data you can judge your methods and returns honestly, because the numbers do not lie.

Why does a trading journal help with self-attribution bias?
A journal forces you to attribute wins and losses the same objective way, in writing, before you can rewrite the story in your favour. A public journal is even stronger, because you cannot quietly delete the trades that embarrass you.

So, be honest with yourself. Do you keep a real record of your trades, or just the highlight reel in your head?

If you want the full set of trading biases and how to beat each one, read the pillar: The Trader’s Guide to Behavioural Finance and Trading Psychology.

Want a routine that keeps you honest? Grab the free 15-Minute Swing Trading Starter Kit. It includes the simple trade-log and review habit I use to scan once a day and trade any market in 15 minutes.

About the author. Spencer Li is the founder of Synapse Trading and a Certified Financial Technician (CFTe) with 15 years of trading across stocks, forex, crypto, commodities, and bonds. His trade log is public, 404 trades, losses left in. He teaches low-risk swing trading in 15 minutes a day, one system for any market.

Education, not financial advice. Synapse Trading is not licensed by MAS to advise on investment products. Trading carries risk of loss; past performance is not indicative of future results.

“Don’t confuse brains with a bull market.”

Related

The Trader’s Guide to Trading Psychology (pillar) · Overconfidence bias in trading · How to keep a trading journal · Confirmation bias in trading · Loss aversion

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Spencer Li

Simple chart-reading can tell you all you need to know

Leonardo Da Vinci once said that simplicity is the ultimate sophistication. Let’s take a moment to ponder that. This applies to research analysis as well. When you hear people talking about some sophisticated trading system or some flashy indicators or some complex wave projections, think again. It is more likely to be smoke and mirrors. All these tell you nothing new if you know how to read the bare charts. It’s as simple as that. Simple, and yet sophisticated. Looking back at my last few stock picks, I found that it is possible to read and understand what is happening on the charts. This makes it possible to pinpoint the low risk entry points, as seen in some of my previous posts.

https://synapsetrading.com/dbs-are-the-banks-leading-the-decline/
https://synapsetrading.com/noble-group-evening-star-signals-turn-to-the-downside/

Compare that with indicators. If you see a green arrow, do you know why it is a buy? Maybe it worked the past 3 times, but will it work this time? Maybe. Or maybe not. You won’t know. In fact, you won’t have any idea why there is a green arrow. You won’t know what is happening in the market. You won’t know what the smart money is doing. That is why chart-reading is an important skill everyone should master. Banks, funds and proprietary trading firms use it as their main tool. Maybe you should consider it too.

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Spencer Li

Representativeness Bias – The Dangers of a Small Sample Size

In order to derive meaning from life experiences, people have developed an innate propensity for classifying objects and thoughts. When they confront a new phenomenon that is inconsistent with any of their preconstructed classifications, they subject it to those classifications anyway, relying on a rough best-fit approximation.

 

Representativeness Bias

 

There are two main types of representativeness bias, namely (i) base-rate neglect and (ii) sample-size neglect. We will focus on the latter, since it occurs more frequently in trading.

In sample-size neglect, traders, when judging the likelihood of a particular trade outcome, often fail to accurately consider the sample size of the data from which they base their judgments. They incorrectly assume that small sample sizes are representative of populations. This is also known as “the law of small numbers”.

This problem is observed when traders try to backtest systems by using small sample sizes of data, and extrapolate their favourable results. However, these results are most likely not representative of the effectiveness of the system. This is a common tactic applied in marketing gimmicks.

Another common phenomenon has to do with hot tips. For example, you might hear someone say “my broker gave me three great stock picks over the past month, and each stock is up by over 10%”. While this is enough to sway most people, thinking that the broker is a genius, this assessment is based on a very small sample size.

What is the best solution for this?

If you want to evaluate the effectiveness of system or the stock-picking skills of a person, make sure you do it over a large sample size, and count both the hits and misses. This will give you a more complete representation of reality.

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Spencer Li

Cognitive Dissonance Bias – This Can’t Be True!

Cognitive Dissonance in Trading: Why You Refuse to Cut a Losing Trade

Last updated: 3 July 2026 · By Spencer Li, CFTe

Cognitive dissonance is the mental discomfort you feel when new information contradicts a position you already hold, and in trading it is the bias that keeps you in a losing trade long after you should have cut it. You buy a stock because you think the trend is up. The chart then prints evidence that the trend is down. Instead of acting on the new evidence, your mind goes to work defending the old decision, because admitting the trade was wrong feels worse than holding the loss. That is cognitive dissonance. It shows up in two forms: you start noticing only the data that supports your trade (selective perception), and you keep making choices that justify staying in it (selective decision making). The fix is not complicated, but it is uncomfortable: the moment you sense the discomfort, name it, look at the trade honestly, and if it is broken, close it. The discomfort is the signal, not the enemy.

Here is what the bias is, why it makes you hold losers, and the exact habit that beats it.

What is cognitive dissonance?

In psychology, a cognition is an attitude, an emotion, a belief, or a value. Cognitive dissonance is the state of imbalance that happens when two cognitions collide. When newly acquired information conflicts with what you already believe, you feel mental discomfort, and the term covers the whole scramble that follows as you try to harmonize the two and make the discomfort go away.

People go to great lengths to convince themselves the decision they already made was the right one, precisely to avoid the discomfort of having been wrong. Psychologists conclude that people perform far-reaching rationalizations to synchronize their cognitions and keep their psychological stability. In plain terms: it is easier to bend the story than to admit the mistake, so that is what the mind does by default.

How cognitive dissonance shows up in a trade

Take a simple example. You go long a stock because you read the trend as up. That is your cognition. Then a new signal appears that favours a downtrend. Now you have two cognitions that cannot both be true, and that imbalance is uncomfortable. Cognitive dissonance kicks in to relieve the discomfort, usually by whispering that maybe the new signal does not really count, or maybe the trend is just pausing, or maybe you were right all along.

You did not change your mind because the chart changed. You changed your reading of the chart to protect the position you already had. That is the trap.

The two kinds of cognitive dissonance bias

The bias splits into two sub-types, and it helps to be able to name which one is running on you in the moment.

Sub-typeWhat it doesWhat it sounds like in your headThe damage
Selective perceptionYou only register information that affirms the course you already chose“See, this one indicator still agrees with me.”You stop reading the market objectively and miss the signals that disagree
Selective decision makingYou rationalize new actions to justify sticking with the original course“I’ll just give it a bit more room, the stop was too tight anyway.”You resist cutting losses and invent excuses rather than admit the entry was wrong

Selective perception filters what you see. Selective decision making bends what you do. Most blown trades use both at once: you stop noticing the evidence against you, and you keep making little decisions that keep you in.

Why this is dangerous for traders

The danger is not subtle. A trader who is not bias-free cannot read the market objectively and cannot adapt fast enough when conditions change. The market does not care which side you took, but cognitive dissonance makes you care, and caring about being right is how you stop seeing what is actually happening.

The most expensive symptom is the resistance to cutting losses. Selective decision making is the machine that manufactures the excuses: the stop was unfair, the news was a one-off, it will come back tomorrow. Each excuse is the mind protecting itself from the discomfort of admitting the initial entry was wrong. The position keeps bleeding while the story keeps improving.

What is the best way to overcome cognitive dissonance in trading?

The key is to immediately admit that a faulty cognition has occurred, address the feeling of unease directly, and take rational action. If you think you have made a bad trading decision, analyse the decision. If the fears prove correct, confront the problem head-on and fix it. Do not negotiate with the discomfort. Use it.

Personally, I treat the unease as a tap on the shoulder rather than something to suppress. The moment a trade starts to feel uncomfortable, that feeling is usually a new cognition arriving before my conscious mind has caught up. The discipline is to stop, look, and ask one question: if I were flat right now, would I put this trade on at this price? If the answer is no, the only reason I am still in it is to avoid admitting I was wrong. That is not a reason to hold.

A few habits make this easier in practice:

  • Decide your exit before you enter, in writing. A pre-committed stop is a decision your unbiased self made for your biased self.
  • Treat being wrong as data, not as a verdict on you. A wrong trade is information about the market, nothing more. The faster you accept it, the faster you adapt.
  • When you catch yourself building an excuse, name it out loud as selective decision making. Naming the bias breaks its grip.

Where the human edge comes in

A screener will flag a broken setup the instant the chart turns against you. It will not feel the discomfort of being wrong, which means it will also not rationalize, hold, and hope. That part is yours. The edge is not in seeing the signal that contradicts your trade, software can do that. The edge is in acting on it before your mind has talked you out of it. That is psychology, the third of the Five Edges, and it is the one no tool can trade for you.

There is a 400-year-old version of this same advice. Shakespeare put it in the mouth of Polonius, advising his son Laertes in Hamlet:

This above all: to thine own self be true,
And it must follow, as the night the day,
Thou canst not then be false to any man.

In trading, being true to yourself means refusing to lie to yourself about a position. The market will tell you the truth. Your job is to listen before the bias edits it.

FAQ

What is cognitive dissonance in trading?
Cognitive dissonance in trading is the mental discomfort that arises when new market information contradicts a position you already hold, and the rationalizing you do to relieve that discomfort. It most often shows up as refusing to cut a losing trade because admitting the entry was wrong feels worse than holding the loss.

What are the two types of cognitive dissonance bias?
The two types are selective perception, where you only register information that confirms the course you already chose, and selective decision making, where you rationalize new actions to justify sticking with your original decision.

Why does cognitive dissonance make traders hold losing trades?
Because cutting the trade means admitting the original decision was wrong, which triggers discomfort. Selective decision making relieves that discomfort by generating excuses (the stop was too tight, the news was a fluke, it will recover), so the trader holds instead of acting on the evidence.

How do I overcome cognitive dissonance when trading?
Admit the faulty cognition the moment you notice the discomfort, analyse the trade honestly, and act on the conclusion. A practical test: if you were flat right now, would you take this trade at this price? If not, the only reason you are still in it is to avoid being wrong, and that is not a reason to hold.

Is cognitive dissonance the same as confirmation bias?
They are closely related but not identical. Confirmation bias is the tendency to seek out information that supports your view. Cognitive dissonance is the discomfort that drives that behaviour once contradictory information shows up, and selective perception is the part of it that overlaps most with confirmation bias.

So here is the honest question to sit with. The next time a trade turns against you and your mind starts building the case for holding, will you notice that you are doing it?

If you want the full set of biases and the routine that keeps them from running your account, read the pillar: The Trader’s Guide to Trading Psychology and Behavioral Finance.

Want the system that takes the emotion out of the exit? Grab the free 15-Minute Swing Trading Starter Kit. It’s the exact once-a-day routine I use to trade any market in 15 minutes, with the rules decided before the market can make me feel anything.

About the author. Spencer Li is the founder of Synapse Trading and a Certified Financial Technician (CFTe) with 15 years of trading across stocks, forex, crypto, commodities, and bonds. His trade log is public, 404 trades, losses left in. He teaches low-risk swing trading in 15 minutes a day, one system for any market.

Education, not financial advice. Synapse Trading is not licensed by MAS to advise on investment products. Trading carries risk of loss; past performance is not indicative of future results.

Related

The Trader’s Guide to Trading Psychology (pillar) · Confirmation bias in trading · Loss aversion and the disposition effect · How to cut losses and let winners run

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Spencer Li

Market Seasonality and Patterns – When is the Best Month to Buy?

One aspect of market analysis is statistical analysis, which is using statistics to find correlations and patterns, where opportunities of skewed probabilities may lurk, giving you an edge over the market in the long run. For investors, this lets you know the best month to start building your portfolio, or to rebalance/adjust your portfolio allocation.

Market Seasonality and Patterns - When is the Best Month to Buy?

Market Seasonality and Patterns – When is the Best Month to Buy?

Seasonality is a characteristic of a time series in which the data experiences regular and predictable changes which recur every calendar year. Any predictable change or pattern in a time series that recurs or repeats over a one-year period can be said to be seasonal.

This is different from cyclical effects, as seasonal cycles are contained within one calendar year, while cyclical effects (such as boosted sales due to low unemployment rates) can span time periods shorter or longer than one calendar year.

For the Singapore stock market, I have done a seasonality study, showing which months are more bullish and bearish. Contrary to popular belief, October is actually a rather bullish month. Every month has its unique characteristics, which skews the probability. As a trader,anything that tilts the probability in our favour is considered an edge.

Here are the results of my research:

Singapore stock market

Some key points to note: the best months for being LONG are April, November and December, while the best months for being SHORT are June, August and September.

There are many other patterns (some less obvious) which could have a significant impact on the stock market. Although your trading decisions should not be based solely on these, they can act as a powerful confirming indicator, or help you adjust your position-aggressiveness.

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