Log parabola charge
Marks bars where an upswing is steepening: the recent half climbs faster than the half before it.
Takes the log of each close over the last window bars (18 by default) and splits them into an early half and a late half. It measures the average log rise per bar in each half; curvature is the late rise minus the early rise. Despite the name, it fits no parabola: it compares two straight-line slopes, and marks a bar only when the late rise, the curvature and a five-bar uptick all clear their thresholds.
How to read it
- Markers sit on the candles where the pattern completes; there is no line or pane.
- A marker means the last stretch of closes is rising faster than the stretch before it, and the last five closes never step down.
- Read it as an upswing that is accelerating now, not as a forecast of where the move ends.
- Expect very few markers at default settings; a lone marker is not a read on its own.
What it outputs
- Accelerating upswing
- Drawn only on bars where the late half rises faster per bar than min_late_slope, bends up by at least min_curvature, and the last five closes never step down.
When it fires
Fires on bars where the late half of the window rises faster per bar than min_late_slope, bends up by at least min_curvature, and the last five closes never step down. It means the rise is steepening now; it does not say where the rise stops. Fired once on the default SPY sample.
Settings
- window
- Bars in the look-back, split into two halves. Raising it measures a slower bend over more bars and marks later; lowering it reacts faster but reads noise as curvature. Values below 6 act as 6.
- min_curvature
- How much faster the late half must rise per bar than the early half. Raising it demands a sharper bend and fires less; lowering it accepts gentler bends and fires more. Negative values let a slightly flattening curve through.
- min_late_slope
- Smallest average log rise per bar over the late half, default 0.00035 (about 0.035% a minute). Raising it needs a faster late climb; lowering it fires on slower rises. Near zero, it fires on any late rise that still bends up.
Pitfalls
- Rare at defaults: one marker in the 20,160-bar SPY sample, about 0.005% of bars. The try presets loosen it, but they are not measured here, so check the marker count after changing them.
- The late slope divides by one more bar than it spans, so it reads low: about 11% at the default 18 bars and 33% at 6. Curvature is biased low too, so the detector is stricter than its thresholds say.
- Thresholds are fixed log slopes per bar, not scaled to volatility, so the same settings mark less on quiet days and more on volatile ones.