Double-bottom Base

Double-bottom Base detects the W-shaped double-bottom base by explicit rules: two sell-offs whose second low undercuts the first without collapsing, a middle peak high in the range after a qualifying advance, and a buy point just above that peak. The Library's first build draws the W, shakeout zone and buy level while the base pends; a dashboard grades proportions and volume character.

How to Trade the Double-bottom Base?

• Reclaim: a close back above the first low is the earliest sign the shakeout is working.
• Handle set: a right-side swing high in the upper half lifts the buy level to the handle high.
• Breakout: a qualifying-volume close above the buy point confirms the base and starts buy-zone and stop tracking; without volume only a caution fires.
• Invalidation / stop: a broken undercut low, a third test of the lows, a stale base or a stop hit end it.

Double-bottom Base Settings

• Swing Detection Length (default 5): pivot span tracing the W.
• Base Length (bars) (defaults 35 to 250) and Base Depth (%) (defaults 10 to 40): allowed age and correction depth.
• Minimum Mid-Peak Position (%) (default 50) and Maximum Undercut (%) (default 8): mid-peak floor and undercut cap.
• Prior Uptrend Filter (default enabled), Uptrend Window (bars) (default 100), Minimum Prior Advance (%) (default 25), Left High Tolerance (%) (default 2): the prior-advance test.
• Pivot Margin (%) (default 0.1): the margin forming the buy point.
• Breakout Volume Confirmation (default enabled), Volume Average Length (default 50), Breakout Volume Multiplier (default 1.4): the volume test.
• Detect Handle Variant (default enabled), Buy Zone (%) (default 5), Fixed Stop After Breakout (default enabled, 7%), Post-Breakout Watch (bars) (default 125): post-detection trade management.
• Dashboard and style toggles: summary panel, W structure, shakeout zone, buy levels and invalidated-base history.

Frequently Asked Questions

How does this differ from the cup-with-handle base?

The cup-with-handle base carves one rounded low and buys near the rim. The W makes two distinct lows, the second undercutting the first, and buys the middle peak.

Why must the second low dip under the first?

The undercut flushes the stops parked at the prior low, removing supply before the right side begins. A second low holding above the first is not flagged, and one collapsing beyond the cap is a decline.

What happens when price clears the pivot without volume?

It fires a caution alert and stays pending. If price then extends above the left-side high without a qualifying breakout, the base is invalidated.