Broadening Formation (Megaphone Pattern): Why Widening Swings Signal a Nervous Market

A broadening formation is what a chart looks like when the market cannot make up its mind and gets louder about it. Each rally pushes to a higher high, each sell-off digs to a lower low, and the two trendlines drawn across those swings spread apart like the mouth of a megaphone. Most patterns traders learn first, triangles and flags, are about prices getting quieter before a move. This one is the opposite. The range keeps widening, and that alone tells us something about the mood of the people trading the stock.

We’ll go through what the pattern is, how to tell a real one from a messy chart, what the published testing says about how it tends to resolve, and a fully worked (hypothetical) trade plan with position sizing in rupees. If you are new to chart reading, our guide to technical analysis for Indian stocks covers the basics this article builds on.

What a broadening formation actually is

Wikipedia’s entry on the broadening top describes it as a chart pattern, also called a megaphone pattern, that turns up in stocks, commodities and currencies. It notes the pattern appears much more often at tops than at bottoms and usually carries bearish implications. Price swings unpredictably inside it, and volume is described as very irregular, giving no real clue about the direction of the next move.

Thomas Bulkowski, whose site ThePatternSite publishes performance statistics on hundreds of chart patterns, sets out the identification rules more tightly:

• Prior trend: price is rising into the pattern, so the trend starts below where the pattern begins.
• Shape: higher peaks and lower valleys, the megaphone look.
• Trendlines: the top line slopes up and the bottom line slopes down.
• Touches: at least five in total, with three peaks or three valleys touching one line and two or more touches on the other.
• White space: price should travel from one side of the pattern to the other, filling the area rather than hugging one edge.

That touch rule matters more than it sounds. Bulkowski points out that it helps avoid a common misreading, where an up-sloping channel with one sharp spike at the end gets mistaken for a megaphone. Two lines that happen to diverge are not a pattern. Five honest touches usually are.

Why widening swings say something about sentiment

Think about who is buying and selling. In a healthy uptrend, dips get bought at roughly the same level or higher, because the people with conviction are still accumulating. In a broadening formation, every dip goes deeper than the last one, yet every bounce still manages a fresh high. Buyers are chasing breakouts, sellers are dumping on each rally, and nobody is defending a level for long.

Wikipedia’s write-up repeats the old market saying that in this formation the smart money is already out and the market is out of control, with big players having done most of their selling early and the wider public doing most of the trading later. Treat that as folklore rather than measured fact. Still, the chart behaviour fits the story: a stock that cannot hold its own previous low is a stock where confidence is thin.

A triangle is a market going quiet before it speaks. A megaphone is a market shouting in both directions at once, and the person who gets hurt most is usually the one who trades the loudest swing.

How the broadening formation develops, step by step

The Wikipedia description uses five minor reversals, labelled a, b, c, d and e. Reversal d forms lower than b, while c and e each form higher than a. In plain terms:

1. The stock rallies and turns down at a first peak (a).
2. It falls to a first trough (b).
3. It rallies past a, making a higher peak (c).
4. It falls through b, making a lower trough (d).
5. It rallies past c to a third, still higher peak (e).

The source is clear on one thing: you cannot be sure of the trend until price breaks below the lower of the two troughs (b and d) and keeps falling. Until that happens, you are looking at a wide, noisy range, nothing more.

What the testing says about the breakout direction

Here is where it gets interesting, because the popular description and the tested numbers do not line up neatly. The folklore says the megaphone is bearish. Bulkowski’s statistics on his broadening tops page, which are based on 1,215 upward-breakout trades and 804 downward-breakout trades in bull markets (US stocks, not Indian ones), say the breakout went upward 60% of the time.

A few more of his bull-market figures, with exactly what each one measures:

• Break-even failure rate: 18% for upward breakouts and 27% for downward breakouts. In his terms, a lower failure rate is better.
• Average move after breakout: an average rise of 42% after upward breakouts and an average decline of 13% after downward ones.
• Throwbacks and pullbacks: 67% in both directions, so about two-thirds of the time price came back toward the breakout level after breaking out. He adds that both hurt performance after the breakout when they appear.
• Hitting the measured target: 66% for upward breakouts and 42% for downward ones.
• Overall rank: 22 out of 39 patterns for upward breakouts and 28 out of 36 for downward breakouts, where 1 is best.

His own summary is blunt: the broadening top is a poor performer, with an above-average break-even failure rate and a below-average rise or decline. So we should not treat it as a high-conviction signal. It is better seen as a warning that the stock’s behaviour has changed, and as a framework for deciding where we are wrong.

Two caveats before you lean on these numbers. They come from US markets, and they come from bull markets. Indian large caps, smallcaps and F&O stocks can behave differently, so use the figures as a rough guide to the pattern’s character rather than as odds you can bank on.

Measuring a target from a broadening formation

Bulkowski’s measure rule is simple. Take the height of the pattern, which is the highest peak minus the lowest valley. Add it to the top for an upward breakout, or subtract it from the bottom for a downward breakout.

He also suggests a more conservative variant: multiply the height by the “percentage meeting price target” figure (66% up, 42% down) and add or subtract that smaller amount instead. Given how often the full target is missed on the downside, the conservative version is the one we would plan around.

Worked example: a hypothetical stock

Everything below is invented to show the arithmetic. It is not a real stock or a recommendation.

Say a mid-cap engineering stock, which we’ll call XYZ Engineering, rallies from ₹600 to around ₹820 over a few months. It then starts swinging. Peaks come in at ₹850, ₹880 and ₹905. Troughs come in at ₹800, ₹780 and ₹760. That is three higher peaks and three lower valleys, six touches in total, comfortably above the five-touch minimum.

Notice how far apart those numbers are. A pattern that is only ₹145 tall produces targets ₹435 apart, from ₹615 to ₹1,050. That spread is the honest picture of what the pattern tells you: something big may be coming, and the chart alone does not know which way.

Three ways traders approach the megaphone

1. Trade the swings inside the pattern

Bulkowski lists an intraformation trade: buy when price rebounds off the lower trendline and sell short near the top when price turns down. He also mentions buying after the third touch of the bottom line once price starts rising, and flags it plainly as a high-risk entry.

Using XYZ, suppose price touches the falling lower trendline near ₹765 and turns up. A trader with ₹5,00,000 in capital who risks 1% per trade can lose ₹5,000. With a stop at ₹745, just under the lower line, the risk is ₹20 a share, so the position is ₹5,000 ÷ ₹20 = 250 shares. If price makes it back to around ₹890 near the upper line, the gain is ₹125 a share, which is 6.25 times the risk.

That ratio looks lovely on paper. The catch is that the lower line keeps falling, so a stop placed just beneath it can be hit by the very next swing, the one that is supposed to make a fresh low. Inside a megaphone, the pattern’s own definition works against tight stops.

2. Wait for the breakout

The more patient route is to wait for price to close outside a trendline, the same discipline you would use on any stock breakout. Take a downward break in XYZ: the stock closes at ₹752, below the ₹760 low. A stop back inside the pattern at ₹790 means ₹38 of risk per share, so the same ₹5,000 risk budget buys about 131 shares (₹5,000 ÷ ₹38 is roughly 131.6, rounded down).

Against the conservative downside target of about ₹699.1, the reward is roughly ₹52.9 a share, or about 1.39 times the risk. Against the full ₹615 target it is ₹137, about 3.61 times the risk. Given the 42% target-hit rate on the downside in Bulkowski’s data, we’d size this as if the smaller number is what we’re likely to get.

If you already hold the stock, a breakdown like this is mostly a signal to protect gains rather than an invitation to go short.

3. Use partial moves as an early hint

Bulkowski also tracks partial rises and declines, where price starts heading toward one trendline and turns back before touching it. In his data, a partial rise works 52% of the time and a partial decline 72% of the time. In one of his examples, a partial decline that works is followed by an immediate upward breakout. He notes that partial moves help predict the breakout direction and let a trader get in sooner, but also raise the risk of failure.

The megaphone rewards the trader who decides in advance where they are wrong. It punishes the one who keeps moving the stop because the next swing “should” turn.

Broadening formation vs triangle: easy to confuse, opposite meaning

A symmetrical triangle has lower highs and higher lows, so the lines converge and volatility shrinks. A broadening formation has higher highs and lower lows, so the lines diverge and volatility grows. Bulkowski lists a related “reverse symmetrical triangle” among the patterns to see alongside it. The practical difference is about stops: in a triangle the range tightens, so a stop just outside it is relatively close. In a megaphone, every swing widens the range, so risk per share keeps rising the longer you wait.

Common mistakes with the broadening formation

• Calling it too early. Two diverging lines after three swings are not enough. Wait for the five touches.
• Assuming it must break down. The folklore says bearish; the tested sample says upward breakouts were more common. Plan for both.
• Using a tight stop inside the pattern. The next lower low is part of the definition, so stops right at the line tend to get taken out.
• Reading too much into volume. Volume in this pattern is described as irregular and not directional, so don’t wait for a clean volume signal that may never come.
• Forgetting position size. As the range widens, keep the rupee risk fixed and cut the number of shares. That is the single habit that keeps a bad megaphone trade small.

Bottom line

The broadening formation is less a trading signal and more a description of a nervous market: higher highs, lower lows, and no side in control. The tested record says it is a middling pattern that breaks upward somewhat more often than not, misses its downside target more often than it hits it, and frequently throws back to the breakout point. Use it to notice that a stock’s character has changed, define your exit before you enter, and keep the size small enough that the next wild swing is an inconvenience rather than a disaster.

Disclaimer: This article is for education only and is not investment advice. The example stock and all prices in the worked example are hypothetical. Pattern statistics quoted are from published US-market research and may not hold for Indian stocks. Please do your own research or consult a SEBI-registered adviser before making any investment or trading decision.