Diamond Top Pattern: A Bearish Reversal Signal

Key Takeaways

• A diamond top pattern combines a broadening phase and a narrowing phase at a market top, forming a diamond outline.
• It is a reversal signal: a close below the lower right trendline points to a downside move.
• Bulkowski finds diamond tops break downward about 54% of the time with an average decline near 17%.
• The measure rule projects the diamond's height from the breakout point to set a target.

What It Is

A diamond top develops after a price rise. In the first half, swings widen into a broadening shape with higher peaks and lower valleys. In the second half, swings contract into a symmetrical triangle with lower peaks and higher valleys. Connecting the turning points draws two lines that diverge and then two that converge, giving the diamond.

Price typically touches each of the four trendlines once or twice. The pattern is often lopsided rather than a perfect diamond, and it can lean to one side, which is normal.

The Intuition

A diamond top captures a market losing its footing at a high. The broadening phase is the loud, emotional part: big swings as bulls and bears fight over a stretched price. The narrowing phase is the truce: swings shrink as the buying that drove the trend dries up.

When the contraction finally resolves downward, it tells you the failed top is giving way. The two-phase structure is what separates a diamond from a plain broadening top or a plain triangle.

How It Works

You confirm a diamond top with a close below the lower right trendline of the contracting phase. Volume often trends downward through the pattern, around 55% to 59% of the time in Bulkowski's sample, and a downside break on rising volume adds conviction.

The measure rule sets a target from the diamond's height:

height = highest peak - lowest valley in the pattern
downside target = breakout price - height

Bulkowski's statistics rank the diamond top near the bottom for performance, last among the patterns he studied in bull markets. Downside breakouts occur about 54% of the time with an average decline near 17%, while upside breakouts average near 29%. Failure rates are about 15% down and 21% up, and throwbacks or pullbacks hit around 57% to 58% of the time. One useful rule: if a near-vertical rise led into the diamond and the break is down, price often falls back to where that rise began.

Worked Example

Suppose a stock climbs to 60 and then carves a diamond. In the broadening phase, peaks reach 62 and 64 while valleys dip to 57 and 55. In the narrowing phase, peaks fall to 61 and 59 while valleys rise to 56 and 57. The highest peak is 64 and the lowest valley is 55, so the height is 9 points.

Price then closes below the lower right line at 57 on rising volume. The downside target is 57 minus 9, or 48. A trader shorts near 57, sets a stop just back inside the diamond around 60, and watches for a throwback to the broken line before the decline extends toward 48.

Common Mistakes

1. Forcing a perfect diamond. Real diamonds are lopsided and tilted. Demanding a symmetric shape makes you miss valid patterns or invent ones that are not there.

2. Trading before the breakout. The diamond is only actionable on a confirmed close beyond the lower right line. Anticipating the break inside the narrowing range gets whipsawed.

3. Confusing it with a megaphone. A megaphone only broadens. A diamond broadens and then narrows. The contraction is the part that gives the diamond its cleaner breakout point.

4. Overrating its reliability. Diamond tops rank poorly in Bulkowski's data, so the average decline is modest and failures are common. Size positions accordingly and respect the stop.

5. Skipping the volume read. A downside break on falling volume is suspect. Look for volume to expand on the breakout to support the move.

Frequently Asked Questions

What is a diamond top pattern in simple terms? A diamond top pattern is a chart shape at a market high where price swings first get wider and then get narrower, drawing a diamond. A break below the bottom right edge warns of a fall.

How does a diamond top pattern affect investment decisions? It flags a possible top, so traders prepare to sell or short on a confirmed close below the lower right line. The diamond's height gives a price target, and a stop sits back inside the pattern.

What is a real-world example of a diamond top pattern? A stock that rallies hard, then chops in a widening range before tightening into a coil at the highs, can print a diamond top before rolling over during a market pullback.

How can investors trade a diamond top pattern effectively? Wait for a close below the lower right trendline on rising volume, project the diamond's height for a target, and place a stop just back inside the pattern. Remember the pattern's modest average decline and plan position size for its high failure rate.

How is a diamond top different from a diamond bottom? A diamond top forms after an uptrend and signals a bearish reversal, while a diamond bottom forms after a downtrend and signals a bullish reversal.

Sources

1. Bulkowski, Thomas. "Diamond Tops." thepatternsite.com. https://thepatternsite.com/diamondt.html
2. StockCharts ChartSchool. "Chart Patterns." https://chartschool.stockcharts.com/table-of-contents/chart-analysis/chart-patterns
3. Investopedia. "Diamond Top Formation." https://www.investopedia.com/terms/d/diamond-top-formation.asp
4. Britannica Money. "Technical Analysis Chart Patterns." https://www.britannica.com/money/technical-analysis-chart-patterns

Disclaimer

This article is educational content only and is not financial advice. Nothing here is a recommendation to buy, sell, or hold any security. Consult a licensed advisor before making investment decisions.