Anchoring Bias in Trading: How Your Entry Price Distorts Decisions

What Is Anchoring Bias in Trading?

Anchoring bias is a cognitive distortion where you rely too heavily on an initial piece of information (the "anchor") when making subsequent decisions. In trading, the most common anchor is your entry price. Once you buy a stock at $100, every evaluation of that stock is filtered through the lens of that $100 number, even though the stock's future has nothing to do with where you bought it.

The stock does not know your entry price. The market does not care about your cost basis. The only thing that matters for future returns is the stock's current price relative to its future value. Yet traders routinely hold losing positions, refuse to sell below their cost, set profit targets based on their entry rather than on chart analysis, and make portfolio decisions anchored to prices that are no longer relevant.

Anchoring bias was first described by psychologists Tversky and Kahneman in 1974. In their experiments, they showed that even random numbers could influence people's estimates of completely unrelated values. If the bias works with random numbers, imagine how powerfully it operates when the anchor is the price at which you committed your own capital.

How Anchoring Manifests in Trading

Fixating on Entry Price

You buy AAPL at $190. Over the next month, it drops to $165. Every day, you calculate your loss relative to $190: "I'm down $25 per share." This calculation is backward-looking and provides zero information about whether AAPL will go up or down from $165.

The relevant question is: "Is AAPL worth more or less than $165 based on its fundamentals, technicals, and macro environment?" Your $190 entry is irrelevant to this analysis. But because $190 is anchored in your mind, it distorts every assessment.

Refusing to Sell Below Cost

This is the most destructive form of anchoring bias. The inner monologue:

"I bought at $100. It's at $80 now. I can't sell at a loss. I'll wait for it to come back to $100 and then sell."

The problems with this thinking:

1. The stock may never return to $100. Plenty of stocks that drop 20% continue to drop 50%, 70%, or go to zero.

2. Even if it does return to $100, the time spent waiting could have been used to deploy that capital profitably elsewhere.

3. The decision to hold is based entirely on the anchor ($100), not on the stock's forward-looking prospects.

4. By the time the stock is at $80, the question is not "will it reach $100?" but "is $80 a good price for this stock?" If the answer is no, sell regardless of your entry.

Setting Irrational Profit Targets

Anchoring also affects the upside. A trader buys at $50 and sets a target of $60 simply because it represents a 20% gain from entry. But $60 might be in the middle of nowhere technically, with no resistance level, no fundamental significance, and no reason to expect the stock to stop there.

Profit targets should be based on chart structure (resistance levels, Fibonacci extensions, prior highs) or valuation (fair value estimates), not on arbitrary percentages from your entry price.

Round Number Anchoring

Traders anchor to round numbers: $50, $100, $500. These levels have psychological significance but not necessarily technical significance. A stock at $98 might have its actual resistance at $103, but traders anchored to $100 sell prematurely because the round number "feels right."

The "Would I Buy Here Today?" Reframe

The most effective tool for overcoming anchoring bias is a single question: "If I had no position and held cash instead, would I buy this stock at today's price?"

This question strips away the anchor entirely. There is no entry price to anchor to. There is no unrealized gain or loss. There is only the stock's current price and its future prospects.

If the answer is yes: Hold the position. You would buy it at this price, so holding is equivalent to buying.

If the answer is no: Sell the position. You would not buy it at this price, so holding is equivalent to choosing this stock over cash (or over other opportunities).

If the answer is "I'm not sure": Reduce the position. Sell half and hold half. This acknowledges uncertainty while freeing up capital.

Applying the Reframe to Real Situations

Scenario 1: You bought XYZ at $80. It is now at $120. Would you buy XYZ at $120 today? If not, take some profit or sell entirely. The $80 entry is irrelevant. What matters is whether $120 represents good value.

Scenario 2: You bought ABC at $50. It is now at $35. Would you buy ABC at $35 today? If the company is still solid and $35 represents a good value, hold. If the thesis has deteriorated and you would not touch it at $35 with fresh money, sell and accept the loss.

Scenario 3: You bought DEF at $60. It is now at $60 after going to $75 and back. Would you buy DEF at $60 today? If yes, hold. If not, sell. Do not anchor to the $75 peak and refuse to sell until it returns there.

Why Your Entry Price Does Not Matter

Your entry price affects exactly two things: your P/L calculation and your tax basis. It does not affect:

• The stock's future price movement
• The company's fundamentals
• Market sentiment toward the stock
• Technical support and resistance levels
• The opportunity cost of your capital

A stock at $80 will do the same thing regardless of whether you bought at $60 (making you feel good) or at $100 (making you feel bad). Your feelings about the position are determined by the anchor, but the stock's behavior is independent of it.

The efficient market hypothesis version: If a stock is fairly valued at $80, it will trade around $80 regardless of what any individual investor paid for it. Your personal cost basis is invisible to the market.

The pragmatic version: Professional portfolio managers evaluate every holding as if they just inherited it today. "Would I buy this at today's price?" is their daily discipline. They do not care about historical cost because it has no predictive value.

Anchoring in Market Analysis

Anchoring bias extends beyond individual positions:

Index Level Anchoring

Traders anchor to previous market levels. "The S&P was at 4,800 last month, so it should go back to 4,800." The market has no obligation to return to any previous level. A new fundamental reality (higher interest rates, economic slowdown, geopolitical shock) may mean the old level is permanently above fair value.

Valuation Anchoring

"This stock used to trade at 30x earnings, so it's cheap at 20x." The stock may have traded at 30x because of growth expectations that no longer apply. Anchoring to historical valuation multiples ignores changing fundamentals.

Price Target Anchoring

Analyst price targets create anchors. If an analyst says a stock is worth $150, traders treat $150 as a ceiling or floor even though the target may be based on assumptions that have changed. Price targets are opinions, not gravity.

Practical Solutions for Anchoring Bias

Solution 1: Pre-Defined Exit Rules

Before entering every trade, define:

• Your stop-loss (based on chart levels, not dollars from entry)
• Your profit target (based on resistance levels, not percentage from entry)
• Your time stop (based on expected setup development time)

Once these rules are set, follow them mechanically. The anchor cannot override a pre-committed rule if you refuse to change the rules after entry.

Solution 2: Trailing Stops

Trailing stops break anchoring by constantly updating your exit level based on the stock's current price rather than your entry price. An ATR-based trailing stop at 2x ATR below the highest high adapts to the stock's actual behavior, not to your purchase price.

Solution 3: Weekly Position Review

Every weekend, review each open position using this framework:

1. Cover the P/L column (do not look at gains or losses)
2. For each stock, analyze the chart as if you have never seen it before
3. Ask: "Does this chart suggest the stock is likely to go up, down, or sideways from here?"
4. Ask: "Would I enter a new position in this stock at this price?"
5. Make hold/sell decisions based on answers 3 and 4
6. Only then look at P/L to process the emotional reaction

This process de-anchors your analysis by evaluating each position on current merit before considering your historical cost.

Solution 4: Focus on Risk, Not Cost

Instead of thinking "I'm down $3 per share," think "My risk from here is $X to my stop-loss." The first frame is anchored to entry price. The second frame is forward-looking and actionable. Whether you are up or down from entry, the only number that matters is how much you stand to lose (or gain) from the current price.

Solution 5: Track Forward Expectancy

For each open position, estimate the expected value of holding vs. selling:

• If I hold: What is the probability of reaching my target? What is the probability of hitting my stop?
• If I sell: What else could I do with this capital? What is the expected return of the next best opportunity?

This calculation forces forward-looking thinking and prevents the backward-looking anchor from dominating.

Anchoring Bias in Different Market Conditions

In bull markets: Traders anchor to the highest price a stock reached and refuse to buy it at a "discount." "I should have bought NVDA at $500, I'm not buying at $800." The $500 price is an anchor. The question is whether $800 is cheap relative to future earnings, not relative to a past price you missed.

In bear markets: Traders anchor to the pre-crash price and hold through massive drawdowns, expecting a return to the old level. "It was at $200 before the crash, it'll come back." Maybe. Maybe not. Evaluate the stock at its current price relative to current fundamentals.

After taking profits: Traders anchor to the exit price and feel guilty if the stock continues higher. "I sold at $150 and now it's at $200." Your sale at $150 was based on your rules at the time. The stock's subsequent move does not retroactively make your sale wrong.

Frequently Asked Questions

Is anchoring bias the same as the sunk cost fallacy?

They are related but distinct. Anchoring bias is about fixating on a reference point (your entry price) when evaluating a position. The sunk cost fallacy is about continuing an action because of resources already invested. In practice, they often work together: the entry price (anchor) makes the unrealized loss feel real, and the sunk cost fallacy makes you hold to avoid "wasting" the money already lost.

Can anchoring bias be beneficial in any way?

Rarely in trading. The entry price can serve as a useful reference for calculating position-level risk-reward before entry. But once the trade is live, the anchor's influence is almost entirely negative. Some traders use their entry as a trailing stop level ("I'll move my stop to breakeven") which is an anchor-based rule that can be either helpful or harmful depending on the context.

How do institutional traders avoid anchoring?

Institutional portfolio managers evaluate holdings at current market value, not at cost. Their risk systems calculate exposure based on current prices. Performance is measured by current portfolio value relative to benchmarks, not relative to purchase prices. Many firms conduct "clean sheet" exercises where they imagine liquidating the entire portfolio and rebuilding from scratch. Holdings that would not be repurchased are candidates for sale.

Does anchoring bias affect options traders differently?

Yes. Options traders anchor to the premium paid, which decays over time regardless of the underlying's movement. A call bought for $5.00 that decays to $3.00 feels like a loss even if the underlying has not moved. The relevant question is whether the remaining $3.00 of option value has positive expected value going forward, not whether it matches the $5.00 paid. Options' time decay makes anchoring bias even more costly because the anchor (purchase price) includes time value that is irreversibly lost.

What if my entire trading system is based on cost basis (e.g., "sell at 20% profit")?

Percentage-from-entry profit rules are inherently anchor-based, but they can still work if applied systematically. The danger is when the anchor causes you to hold through a reversal because the 20% target has not been hit. Consider supplementing percentage-from-entry rules with chart-based exits (trailing stops, support breaks) that override the fixed target when the technical picture deteriorates.