Head and Shoulders: You Draw the Neckline
A head and shoulders is a three-peak formation with a higher middle peak, completed when price breaks the neckline drawn under the two intervening lows. Which peaks qualify and where the neckline sits are both decisions made by the person drawing it, which is where most of the pattern's apparent reliability comes from.
How it works
Three peaks in sequence. The first and third are roughly level — the shoulders — and the middle one is higher, the head. The two lows between them define a line called the neckline.
The pattern is complete when price breaks below that neckline, and it is read as the end of an advance: buyers made a higher high, failed to make another, and then failed to hold the level that had been supporting the whole structure.
The neckline is a line you draw. Two lows define it, and which two lows are “the” lows is a judgement. Move one choice by a few bars and the line tilts, the break happens at a different price, and the measured target changes.
Every step is a judgement, and that is the subject
Which peaks count as shoulders? There is no threshold. A minor high three bars wide and a major high thirty bars wide both look like peaks on the right chart, and the pattern does not specify a minimum size.
How level must the shoulders be? Also unspecified. “Roughly equal” covers a range of a few percent on most charts, which on a volatile instrument is a great deal of latitude.
How much retracement between them? Unspecified again.
The textbook picture is symmetrical and real charts are not. Actual formations have uneven shoulders, sloping necklines and different durations either side of the head. Every judgement call gets made in the direction of the pattern you are already looking for, which is not dishonesty — it is how pattern recognition works, and it is why the rules have to be written down first.
On this site’s shared history the average run of consecutive closes in one direction is 2.01 bars, and the longest is 11. So on a fast chart, most “shoulders” are two- or three-bar wiggles that would not have been named at all if the surrounding shape had been different.
In practice: the parts that are actually specified
The measured move is the one piece of arithmetic in the pattern. Take the vertical distance from the head to the neckline, and project it downward from the break point. That is the target.
It is arithmetic, not a forecast. Nothing about the geometry of a completed shape creates an obligation for price to travel a matching distance. What the target does provide is a way to decide in advance whether the trade is worth taking, given where the stop has to go — and that is genuinely useful even if the target is never reached.
The retest is the only entry with a defined risk. Price breaks the neckline, returns to it, and fails there. That gives an entry near the line with a stop just above it, which is a much smaller distance than entering on the break with a stop above the right shoulder.
It also frequently does not happen, and waiting for it means missing the moves that run straight down. That trade-off is real and unresolvable; what matters is deciding which version you are trading before the break, not after.
The conventional stop is above the right shoulder, because that is the price which invalidates the structure. On a formation of any size, that is a long way from a neckline entry — which caps position size and is the main reason the pattern’s apparent hit rate matters less than people think.
The classical volume reading is that participation declines through the formation — heaviest on the left shoulder, lighter on the head, lightest on the right. It is the one part of the pattern that uses an input other than price, and it is the part most often skipped.
Aggregate the chart and the formation vanishes. Thirty daily bars become six weekly bars, and six bars cannot show three peaks and two troughs with any clarity. The pattern exists at the timeframe you chose to look at.
A gap through the neckline completes the pattern at a price you could not transact at, and removes the retest entry entirely. The pattern “worked” and the trade was unavailable — a distinction that backtests on closing prices tend to lose.
Each attempt costs 2% of a typical bar’s range in round-trip costs on this history, which is small relative to the pattern’s own scale — one of the few advantages of a formation that takes weeks to build.
And no order exists in the order book because a shape acquired a name. If the neckline produces reaction, it is because it is a visible horizontal level that many people drew in roughly the same place — the same self-fulfilling mechanism that operates on any obvious level, and no more than that.
What a head and shoulders is not
It is not a rule. It has no numeric thresholds anywhere in its definition, which means two competent people can disagree about whether one exists on the same chart.
It is not complete before the break. “A head and shoulders is forming” is a prediction about the future stated as an observation about the present.
It is not a double top. That is two peaks at similar heights. This requires a higher middle peak, and the difference is the whole structure.
And it is not more reliable for being famous. Its familiarity is why it gets found everywhere, which is a reason for more caution rather than less.
When it fails
In a range the pattern is everywhere. Price oscillates between boundaries, so sequences of three peaks with a higher middle one occur constantly by chance. A shape you can find anywhere is not constraining your decisions.
The second failure is redrawing the neckline after the break. Price breaks, then recovers, and the line gets adjusted to the next low so the pattern is “still valid.” At that point the pattern has become unfalsifiable.
A third is the right shoulder that keeps forming. Until price breaks the neckline, the formation is incomplete, and a right shoulder can extend indefinitely — often into a new high that destroys the structure entirely.
A fourth is entering on the break without a plan for the retest. Break entries have wide stops; retest entries frequently never trigger. Choosing between them after seeing which happened is deciding with hindsight.
And a fifth is treating the measured target as a probability statement. It is a distance derived from the shape. Price reaching it, exceeding it or ignoring it are all ordinary outcomes, and the target’s value is in sizing the trade beforehand, not in expecting the number.
The original data
The relevant measurement for this pattern is not a hit rate — it is how long directional moves actually last on the data underneath it. On this site’s shared 576-bar history there are 286 directional runs, averaging 2.01 bars, with the longest at 11 bars.
That figure is the reason the peak-selection problem is not academic. With runs that short, a
574-bar chart contains hundreds of local peaks, and any three of them in the right arrangement satisfy an
unquantified pattern definition. Write down what counts as a peak — a minimum number of bars, a minimum
retracement — before you go looking, and the number of head and shoulders formations on your chart falls
by an order of magnitude. That single constraint does more for this pattern than any refinement of what
to do after the break, and the run statistics are in research/series-measurements.json if you want to
calibrate it.
Related
Chart patterns is the parent page on named shapes and how much of them the observer supplies. Inverse head and shoulders is the mirror formation. And reversals covers the event this pattern is trying to identify.
I could draw a head and shoulders on almost any chart you handed me, and for a while I thought that was skill. It is the opposite: a pattern I can always find is a pattern that is not constraining my decisions, and the discipline that fixed it was writing the peak-selection rule down before opening the chart.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.