Explosive parabolic detector

A 0 to 100 surge score that sits near 25 on ordinary bars and mostly ignores whether price is rising or falling.

The score adds four capped parts: acceleration of the last four one-minute changes (up to 35), how often a bar's percent move beats the one before it across the window (up to 30), current volume against the earlier bars' average (up to 25), and a two-bar gain that needs about 0.5% to score a single point (up to 10). The acceleration part needs each change to be larger than the one before, in signed dollars, so a fall that is slowing down scores the same as a rally that is speeding up. The percent-move part is close to a coin flip on noisy bars, which is why an ordinary chart reads about 25.

How to read it

The line sits in its own pane below the price, scaled 0 to 100. It is a score, not a price level.
On SPY one-minute bars for September 2026 the median bar read 25, the top 5% read 50 or more, and the highest was 90.
Readings above 50 were rare there, so check the price beside a high reading to see whether the surge is up or down.
The first bars of a chart read 0 while the window fills (11 bars at the default), which is not a flat reading.

What it outputs

Parabolic score: A 0 to 100 score of how much recent one-minute bars look like an accelerating surge. Higher means more of its four parts fired at once.

Settings

window: Bars looked back over. Below 5 almost nothing scores, as three parts need 5 bars. From 5 to 8 the percent-move part has few comparisons, so it swings more. Above about 20 that part pins at its 30-point cap, so typical readings sit near 30 and flatten.

Pitfalls

The score is direction-blind: the acceleration and percent-move parts reward a slowing fall as much as a speeding rally, so check the price beside it before reading it as upside.
About half of percent moves beat the one before, so that part adds about 25 points to ordinary bars at the default window. The score is not a probability and has no built-in signal threshold.
The acceleration part is in absolute dollars (scaled by 10,000), so the same shape scores far less on a cheaper stock and cannot be compared across symbols.