Big W

Core idea

A Big W is a double bottom with a tall left side. Price drops in a steep, often straight-line run from launch A to the first valley B, recovers to a hill C, drops back to a roughly equal second valley D, then rises. The pattern confirms — i.e. becomes a Big W — only when price closes above the hill between the two valleys. It breaks out upward by definition.

The "tall left side" requirement is what separates Big Ws from ordinary double bottoms: it gives the pattern a measurable upside. In bull markets, the average rise after breakout is 46% (rank 11 of 20 — solid mid-table). Bear-market upward breakouts average 30%. Breakeven failure rate is just 9% — among the better numbers in the Encyclopedia.

Where the edge comes from

A double bottom in any context is a defensible buy, but a Big W in particular benefits from the prior decline. The steep left side often leaves bargain hunters and short-covering buyers waiting in the wings; when the second bottom holds and the hill breaks, both groups buy at once. Confirmed Big Ws near the yearly low outperform Big Ws near the yearly high — bottom-fishing context beats momentum context for this pattern.

Why it matters

The Big W slots cleanly into Bulkowski's preferred bottom-fishing method (How to Trade Chart Patterns). The pattern's geometry tells you entry (close above the hill C), stop (below the lower of the two valleys), and target (measure-rule height added to breakout, or the launch price A as a stretch goal). Two-thirds of patterns throw back to the breakout within ~12 days; trades that survive the throwback tend to deliver the full 46% average.

Key takeaways

Mental model — anatomy of a Big W

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Identification guidelines

• Steep left side. A long, straight drop from launch A to first valley B. Patterns that drift down sideways are double bottoms, not Big Ws.
• Twin valleys. Two bottoms at roughly the same price (median variation 14 cents).
• Tall left side test. The drop from C (central hill) to B should fit at least once into the rise from A to C. In other words, the left side from A to B should be at least as tall as the height of the W itself.
• Confirmation. A close above the high of the central hill C. Without it, no pattern.
• Volume. Trends downward from valley B to valley D ~69% of the time. Direction does not bar identification.
• Duration. Bulkowski observed widths from 4 days to 260 days. Wide range; no fixed cap.

How the pattern fails

1. 5% failure. Upward breakout that rises ≤5% before reversing (~9% of patterns).
2. Busted Big W. Price breaks out up, then closes below the lower of the two valleys. The pattern's edge collapses; the prior downtrend often resumes.

Practical application

A long trade plan

1. Identify two valleys at similar prices with a tall left side. Mark launch A, valleys B and D, hill C.
2. Wait for a close above hill C — the confirmation. Buy on the next open, or use a buy-stop a penny above C.
3. Stop below the lower of the two valleys (B or D).
4. Expect a throwback (~67%) within ~12 days. Hold through it if the structure stays intact.
5. First target: hill C + half the pattern height. Second target: A (launch price). Stretch: C + full pattern height (measure rule).
6. Bust check: a close below the lower valley after the breakout invalidates the pattern. Exit immediately.

Picking the right Big W

Bulkowski's empirical filters compound:

• Near the yearly low? Yes. Bottom-fishing context is the strongest performance edge for this pattern.
• Throwback expected? Look for overhead resistance — prior peaks, round numbers, sideways chop between the breakout and ~10% higher. If present, expect a throwback and plan for it.
• Gap on breakout day? Slight performance edge, more in bear markets than bull.
• Volume trend across the W? Downward is typical; upward (rarer) does not penalise performance.

Example: a fictional pharma name after a sector selloff

A fictional pharma PHA collapses from A = 80 in February to B = 50 in March (a 38% drop in five weeks — clearly the "steep, straight-line decline" the Big W requires). Recovers to C = 62 in April. Tests D = 50.50 in May. Closes above 62 on heavy volume in June (breakout).

Trade: buy 62.50 on the breakout. Stop 49.50 (just below the lower of the two valleys). Pattern height = 62 − 50 = 12; measure-rule target = 74; launch target = 80. Risk = 13, reward to measure = 11.5 (0.9:1), reward to launch = 17.5 (1.3:1).

The 67% throwback brings price back to ~62 in early July. The trader holds, since structure is intact and PHA sits in the bottom third of its yearly range. Late July, price resumes and reaches 74 (measure target). The trader scales out half, trails the rest with a 20-day low. Final exit near 78 — short of launch but inside the 46% average.

Where this fits in the family

The Big W is the bullish twin of the Big M (Big M). It is the non-Fibonacci counterpart to the bullish bat (Bat, Bullish) — easier to find, looser ratios, similar average upside. In Bulkowski's working method (How to Trade Chart Patterns), the Big W is a textbook "diving board" variant when the recovery from the second valley forms its tall right side.

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