Double Bottom¶
A double bottom is a bullish reversal pattern shaped like the letter W, formed when price tests a support level twice with a moderate rally between the two lows. The pattern signals that sellers failed to push price below support on the second attempt — buying pressure absorbed the test and exhausted the downtrend.
Note
Thomas Bulkowski's pattern encyclopedia places the double bottom's upward break-out rate at 64% with an average post-breakout gain of 38%, making it one of the more reliable reversal formations in the technical playbook.
HOW TO IDENTIFY A DOUBLE BOTTOM¶
The pattern requires six elements:
| # | Element | Requirement |
|---|---|---|
| 1 | Preceding downtrend | At least 10% decline to establish reversal context |
| 2 | First low (Bottom 1) | Establishes the support level |
| 3 | Interim rally (neckline) | Typically 10–20% above Bottom 1 |
| 4 | Second low (Bottom 2) | Within ~3–4% of Bottom 1; slightly higher is more reliable |
| 5 | Time between bottoms | 2 weeks to several months; tightly clustered bottoms (under a week apart) are noise, not structure |
| 6 | Confirmation | Daily close above neckline on volume ≥20% above 20-day average |
Tip
A slightly higher Bottom 2 outperforms perfectly equal lows according to Bulkowski's data. Do not require price symmetry as a validation condition.
Measured-move target: Height from bottoms to neckline, added to the breakout price.
WORKED EXAMPLE: AMD 2022–2023¶
Advanced Micro Devices printed a textbook double bottom in late 2022:
- Bottom 1: $54.57 — October 13, 2022
- Neckline peak: $77 — November 14, 2022
- Bottom 2: $63.40 — December 28, 2022 (higher low — pattern strengthened)
- Neckline breakout: Early January 2023 on heavy volume
- Measured-move target: $77 + ($77 − $54.57) = ~$99
- Actual result: $97 by mid-February; $132 by mid-July (+33% beyond target)
Note
Traders who entered on the neckline breakout with stops below $63.40 had a risk-reward of ~2:1 to the measured move and over 4:1 to the eventual peak.
WHEN TRADERS USE DOUBLE BOTTOMS¶
| Context | Description |
|---|---|
| Trend reversal entry | Established downtrend prints the W structure and breaks the neckline |
| Support confirmation | Reinforces a key floor and validates accumulation in sideways markets |
| Multi-timeframe alignment | Weekly double bottom backed by a daily break of structure — high-conviction swing setup |
Stop placement: A few percent below Bottom 2.
Position sizing: Use the neckline-to-stop distance as the risk unit.
LIMITATIONS AND MISCONCEPTIONS¶
| Failure Condition | Detail |
|---|---|
| False breakout | 36% failure rate; neckline can flip to resistance after break |
| Bottoms too close | Patterns under two weeks apart are noise, not structure |
| Low breakout volume | Contracting volume on breakout significantly reduces reliability |
| Shallow downtrend | Preceding decline under 10% invalidates reversal context |
| Confusion with rectangles | A valid W requires a distinct interim peak, not a sideways base |
Tip
Do not confuse a double bottom with a rectangle consolidation. The W shape depends on a clearly defined neckline peak between the two lows.