What is a Head and Shoulders Pattern? Definition, Formula, and Example
A head and shoulders pattern is a bearish reversal chart formation with three peaks—a higher middle peak (the head) flanked by two lower peaks (the shoulders)—that signals a downtrend when price closes below the connecting neckline.
What is a Head and Shoulders Pattern?
A head and shoulders pattern is a bearish reversal chart formation built from three sequential peaks: a higher middle peak (the "head") flanked by two lower peaks (the "shoulders") at roughly equal heights. The pattern completes when price closes below the "neckline"—the trendline connecting the two troughs between the peaks—signaling that the prior uptrend has exhausted and a downtrend has begun. The inverse pattern, with three troughs instead of three peaks, is a bullish reversal called an inverse head and shoulders.
How a Head and Shoulders Pattern is Identified
Five components must be present for a valid pattern:
1. Prior uptrend — the formation is meaningful only at the top of an existing rally.
2. Left shoulder — first peak, formed on rising volume.
3. Head — higher peak, often on weaker volume than the left shoulder.
4. Right shoulder — peak at roughly the same height as the left shoulder, on visibly lighter volume.
5. Neckline — the line drawn through the two troughs between the three peaks.
Confirmation requires a daily close below the neckline, ideally on expanding volume. The price target is calculated by measuring the vertical distance from the head to the neckline and projecting that distance down from the breakdown point:
Target = Neckline − (Head − Neckline)
Worked Example: Tesla, November 2021 – May 2022
TSLA printed a textbook head and shoulders during its 2021 top:
- Left shoulder: ~$370 (early November 2021)
- Head: $414.50 (November 4, 2021)
- Right shoulder: ~$385 (late December 2021)
- Neckline: ~$340
The breakdown occurred on January 19, 2022, when TSLA closed at $338 on volume 28% above the 20-day average. Pattern target = $340 − ($414.50 − $340) = $265.50. TSLA hit $264.81 on May 11, 2022, satisfying the projection within 16 weeks of the neckline break.
When Traders Use the Pattern
- Trend-reversal identification — flagging exhaustion in extended rallies.
- Risk-defined short setups — entering short on the neckline break with a stop above the right shoulder, giving a fixed risk-per-share.
- Profit targets — the measured-move projection produces a quantified objective rather than an arbitrary level.
- Position sizing — the distance between the breakdown and the right shoulder defines maximum loss before adding capital.
The inverse pattern is used the same way at market bottoms, with stops placed below the right shoulder and longs initiated on a neckline reclaim.
Limitations and Common Misconceptions
- Subjectivity — identification varies between chartists; pattern-recognition algorithms often disagree on the same chart.
- False breakdowns — roughly 35-40% of head and shoulders patterns fail and reverse back through the neckline within a few sessions.
- Volume requirement — patterns that break the neckline on light volume have substantially lower follow-through than those breaking on volume above the 20-day average.
- Not a top in isolation — works only as a reversal in an existing uptrend; horizontal price action that resembles the pattern carries no statistical edge.
- Time symmetry matters — the pattern is more reliable when the two shoulders form over similar timeframes; lopsided shoulders weaken the signal.
- Neckline slope — descending necklines produce stronger breakdowns than horizontal or ascending ones.