Confirmation bias in trading is the habit of looking for, noticing and believing the evidence that supports a trade you already like, while discounting the evidence against it. From the inside it feels like good analysis, which is why it costs traders money.
Quick answer: how do you reduce confirmation bias in trading?
Before every trade, write down the price that would prove the idea wrong and the strongest argument against it. Check both against a fixed set of rules that you cannot change while the trade is open. Afterwards, review every trade, not only the ones that fit the story you tell yourself.
What confirmation bias in trading looks like
Psychologists describe confirmation bias as favouring information that fits what we already believe. In trading, the belief is usually a direction: “the pound is going up”. Once that view is in place, the chart starts to look different.
- Timeframe shopping. The daily chart says no, so you drop to the hourly until something says yes.
- Indicator shopping. You add tools until one agrees, then call it confirmation.
- Selective reading. You remember the analyst who agrees with you and skim past the one who does not.
- Reading every candle as support. In an open trade, a pause is “accumulation” and a sharp drop is “a shake-out”.
- Story-friendly reviews. You study the trades that prove your skill and skip the rest.
Why our brains do it
This is not a character flaw unique to traders. A 2020 study in Nature Neuroscience found that people failed to use the strength of disagreeing opinions to change their confidence, yet did use the strength of agreeing ones. Brain activity linked to weighing the strength of others’ opinions was weaker when those opinions disagreed.
The experiment was not about markets, but the pattern is easy to recognise. A confident post in a trading group that agrees with your position lands hard; an equally confident post that disagrees barely registers. Leverage then turns that uneven weighing into real losses.
Where it fits among other trading biases
Confirmation bias rarely acts alone. We cover the five psychological hurdles we see most in our guide to the psychological hurdles traders face, including overconfidence. The table below shows how confirmation bias differs from a few related cognitive biases in trading. Another common one after a run of losses is the gambler’s fallacy in trading. Another is anchoring bias in trading, where one number shapes every later decision.
| Bias | What it does | Typical trading sign |
|---|---|---|
| Confirmation bias | Filters evidence to fit a view | Only bullish reasons in your notes |
| Anchoring | Sticks to the first number seen | Waiting for an old price to return |
| Hindsight bias | “I knew it all along” | Reviews that make every loss look obvious |
| Sunk cost | Values what is already spent | Holding a loser because of the time invested |
Before the trade: analysis that argues back
The best moment to deal with the bias is before you have money on the line. We build the opposing case into the process so it does not depend on mood.
- Write the idea in one sentence. Market, direction and the reason.
- Write the invalidation price. The level where the idea is plainly wrong, which also sets the stop.
- Write the best case against it. At least two specific reasons, as if a colleague were arguing the other side.
- Fix your timeframes in advance. Decide which charts you will read before you look, and do not add others.
- Run the same checklist every time. Our filters and triggers entry checklist is one model; the point is that it is fixed.
If you cannot argue against the trade, you have not looked hard enough. Reading a top-down view across several timeframes in a fixed order makes the opposing evidence harder to avoid.
During the trade: protect the stop from your opinion
An open position is where confirmation bias does the most damage. Every new candle gets read in the trade’s favour, and the stop starts to look “too tight”. Our guide on where to place a stop loss with price action covers placement; the rule here is simpler: the stop was set by the invalidation price, so only price can change the idea.
If you notice yourself searching for news or posts to justify staying in, treat that as a warning sign rather than research. The emotional side of this, and a daily routine for it, is covered in how to stop emotional trading.
Worked example: the stop that moved
Example (hypothetical): on a £5,000 account, a trader is bullish on a currency pair and buys at a spread bet stake of £1.25 per pip. The planned stop is 40 pips away, below the last swing low, so the planned risk is £50, or 1% of the account.
Price falls towards the stop. The daily chart now shows a bearish engulfing candle at resistance, which the trader had noted but played down. Instead of accepting the loss, they read a bullish comment in a trading group, decide the drop is a shake-out and move the stop to 80 pips.
Price hits the new stop. The loss is £100, double the plan, and 2% of the account on one idea. Spread bets and CFDs are leveraged, and a gap can fill a stop at a worse price than set, so the real loss could be larger still.
The fix is not more willpower in the moment. It is the rule written beforehand: the stop only moves in the trade’s favour, never away. Our guide to following your own trading rules covers how to make rules like that stick.
After the trade: reviews that do not flatter you
Bias also edits your memory. Reviewing only the trades that confirm your skill tells you that you are always right. Two habits help.
- Add a “what would make this wrong?” column to your trading journal for beginners, filled in before entry, then compare it with what happened.
- Review every trade at a fixed time, not only the memorable ones. Our weekly trading review routine sets out a simple structure.
The same applies to testing. If you tweak a strategy until past results look good, you have confirmed your idea rather than tested it; our guide on how to backtest a strategy without fooling yourself explains how to avoid that.
Common mistakes
- Thinking a market view is the problem. Having a view is fine; refusing to write what would prove it wrong is the problem.
- Following one voice. A single analyst or group that always agrees with you is an echo chamber, not research.
- Counting indicators as votes. Three tools built from the same price are one opinion, not three.
- Chasing a move to prove a view right. That turns bias into FOMO, covered in our article on fear of missing out in trading.
Frequently asked questions
What is an example of confirmation bias in trading?
A trader expects a market to rise, so they focus on a bullish candle on the hourly chart and ignore a clear rejection from resistance on the daily. The trade feels well researched, but the evidence was chosen to fit the view.
Can you get rid of confirmation bias completely?
No, it is part of how people process information. You can limit its effect by writing the opposing case and invalidation price before each trade and using rules that do not change mid-trade.
Is confirmation bias the same as overconfidence?
They are related but different. Overconfidence is believing you are more skilled or accurate than you are; confirmation bias is how you collect evidence, and it often feeds overconfidence.
Do trading groups make confirmation bias worse?
They can, if you only listen to people who already agree with you. A group helps when members challenge each other’s ideas with specific levels and reasons.
Next steps
For your next five trades, write the invalidation price and two reasons against each one before you enter. Then read our guide to the five psychological hurdles in trading for the wider picture, and our step-by-step guide to creating a trading plan with fixed rules.
The five key psychological hurdles and a filters and trigger process are both part of our price action trading course, and the basics section is free to start.
This article is for education only and is not financial advice. Trading leveraged products such as CFDs and spread bets carries a high risk of losing money.
