Diamond Top and Bottom — A Rare Pattern of Fast Reversals

The diamond pattern holds a legendary status in technical analysis: supposedly rare, supposedly powerful, supposedly "reliably nails the tops." Bulkowski himself writes that diamonds are as hard to spot as earthworms in the grass on a summer night — and that part, at least, is true. The rest of the legend needs to be checked against the table, because the data show something more interesting than the myth: the diamond can be both the best and the worst pattern in the catalog — depending on the variant and the breakout direction.

Specifically: diamond bottom with a downward breakout has rank 1/36 — first place among all bearish patterns. Diamond top with an upward breakout has rank 39/39 — last place among all bullish patterns. Same shape, opposite ends of the table. Anyone who says "the diamond works" or "doesn't work" without specifying the variant isn't saying anything.

How to Identify a Diamond Pattern

The diamond is a hybrid: a megaphone morphing into a symmetrical triangle. Bulkowski's criteria:

1. Phase one — expansion: increasingly higher highs and increasingly lower lows; the trading range widens as in a broadening formation.
2. Phase two — contraction: at some point the highs start falling and the lows start rising; the range narrows as in a symmetrical triangle.
3. Trendlines through the extremes form a rhombus. In practice — and this matters — a diamond almost never looks like the textbook version: it's usually tilted to one side, resembling a leaning square more than anything. One or two touches on each of the four lines is enough; a single outlier wick can cross a line.
4. The variant depends on the trend before the pattern: price enters from below (after a rise) → diamond top; from above (after a decline) → diamond bottom.
5. Premium context: a fast move before the pattern. The diamond's signature move is "a fast decline after a fast rise": a nearly vertical rally, a diamond, a downward breakout — and a drop back toward the point where the rally started. Mirrored for the diamond bottom.
6. Volume usually falls during the pattern (55–67% of cases depending on the variant).
7. Confirmation: a close outside the bounding line. Diamond bottom breaks upward 74% of the time; diamond top breaks downward only 54% of the time.

What the Numbers Say (Bulkowski, Encyclopedia of Chart Patterns)

Terms: failure rate — how often price, after a confirmed breakout, didn't even move 5% in its direction; average move — from breakout to extreme, on perfect trades; throwback/pullback — a return to the breakout line within 30 days; target % — how often the measure rule works.

Bull market; diamond top: n=733; diamond bottom: n=477.

Conclusions, one at a time:

Diamond bottom is the stronger sibling. It breaks out upward 3 times out of 4, with a 13% failure rate, an average rise of 39% and — a rarity in the catalog — the target hit 73% of the time. And when it exceptionally breaks downward, it's the best bearish pattern in the entire catalog (rank 1/36). Bonus: throwback only 52% of the time, the least "jarring" result in the table.

Diamond top is overhyped as a standalone short signal. A downward breakout 54% of the time is nearly a coin flip — far from a "reliable top-catcher." True, once it does break downward, quality is high (rank 3/36, 15% failure rate, 63% target hit), but you have to wait for the direction. And the opposite variant is a heavyweight warning: diamond top breaking upward is the last-ranked bullish pattern in the catalog (39/39) with a 21% failure rate — chasing such a breakout is statistically the worst long in the catalog.

The fast-move rule. Bulkowski's most practical observation: if a diamond follows a fast, nearly vertical move and the breakout goes in the direction opposite to that move, price usually returns to the area where the move started (though more slowly than it got there). That's a ready-made, concrete target. Condition: there has to be something to reverse — diamonds after trends shorter than 6 months work best.

Half-staff. When the diamond acts as a continuation (price exits in the same direction it entered), the pattern sometimes behaves like a "flagpole halfway up the move" — though the second leg often turns out shorter than the first, so look for support/resistance along the way.

Disclaimer: US stocks, daily chart, bull market. Nobody has rigorously measured diamonds on intraday crypto.

How to Trade a Diamond Pattern

Step zero: make sure it's actually a diamond. Half the "diamonds" you see online are megaphones, triangles, or plain noise with a rhombus drawn on top. You need both phases — expansion and contraction — plus touches on all four lines. Tilt is normal; a missing expansion phase disqualifies it.

Setup one (the best): diamond bottom after a fast decline. Long entry on a close above the upper-right edge of the rhombus (statistics on your side: 74% upward breakouts). Stop below the diamond's lowest point. Base target: the measure rule — pattern height (highest high minus lowest low) × 73%, projected from the breakout point. A more ambitious target if there was a fast decline before the pattern: a return to the area of the decline's base — Bulkowski notes price often gets "close" to it, so take some profit a bit earlier.

Setup two: diamond top after a vertical rally — but only after confirmation. Short on a close below the lower-right edge. Stop above the last high inside the rhombus. Target: the base of the pre-pattern rally, or the measure rule × 63%. Without a close outside the line there's no trade — remember, 46% of breakouts go up.

What not to trade: longs on an upward breakout from a diamond top (rank 39/39 — the statistical bottom of the catalog) and "diamonds" forced into existence. The pattern really is rare; if you're finding three a week, that's not the market handing out opportunities — that's you drawing rhombi.

Management: moves after a diamond tend to be fast (high speed before the pattern → high speed after it), so a trailing stop makes more sense here than a fixed target. A pullback after a downward breakout shows up roughly 58–67% of the time — don't be surprised by it.

Myth vs Measurement

Myth: "The diamond is a rare but reliable reversal signal — diamond top catches tops better than head and shoulders."

Measurement: diamond top breaks downward 54% of the time. Reliability at catching tops on par with a slightly loaded coin. The diamond's real strength lies elsewhere: in conditional scenarios — diamond bottom with an upward breakout (74%, +39%, 73% target hit) and both variants AFTER the direction is confirmed, especially after a fast move before the pattern, where you get a rare luxury: a concrete, measurement-backed target (the base of the prior move).

Where does the myth come from? Rarity does the work of quality. There aren't many of these patterns, so every remembered case tends to be the spectacular one — a vertical rally, a rhombus, a 30% drop. Nobody collects the diamonds that broke out upward and kept sailing north, and that's nearly half of them. On top of that, the diamond looks pretty — and a pattern's beauty has never correlated with its effectiveness.

No sugarcoating: the diamond is a pattern for patient traders with a good eye — hard to find, easy to force into existence, excellent only in specific variants. If you're not sure you're looking at a rhombus, you're not. And if you are — wait for the close outside the line, because only that tells you which end of the ranking table you're actually looking at.

FAQ

How do you identify a diamond pattern? Two phases: expansion (like a megaphone), then contraction (like a symmetrical triangle); trendlines through the extremes form a rhombus, usually tilted to one side. One or two touches per line is enough; a missing expansion phase means it isn't a diamond.

Does a diamond top predict a crash? It breaks downward only 54% of the time — nearly a coin flip, so there's no signal without confirmation. After a confirmed downward breakout, quality is high (rank 3/36), and with a vertical rally before the pattern, the target is the area of that rally's base.

Which variant is the strongest? Diamond bottom: 74% upward breakouts, +39% average rise, target hit 73% of the time — and its rare downward breakout is rank 1/36, the best bearish pattern in the catalog. The weakest: diamond top with an upward breakout — last place (39/39) among bullish patterns.

FAQ

Rafał — Krypto Bez Ściemy

Trader and founder of Strefa Tradingu. He’s been breaking crypto down on YouTube for years — no hype, no signals, with a focus on market structure and risk management.

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