Parabolic acceleration
Marks bars where the price path has curved upward for four bars running, whether rising or falling.
ParabolicAcceleration keeps the recent one-minute closes and compares each price change with the change before it. It marks a bar only when the last four changes each grew, and their average growth is above $0.001. The test reads curvature, not direction, so a fall that is losing steam qualifies as well.
How to read it
- Markers sit on the candles where the pattern completes, drawn at that bar's close, so they confirm a bend that already happened.
- An upward curve means each one-minute change is larger than the last: a rally getting steeper or a selloff losing steam.
- Default settings mark about 3% of bars, roughly 26 a day on SPY in September 2026. Most markers last a single bar, so read a run of consecutive markers as one event.
What it outputs
- Acceleration
- A marker on each bar where the last four one-minute price changes were each larger than the one before. Drawn at that bar's close.
When it fires
The bar's close completes four one-minute changes that each grew on the one before, with average growth above $0.001. It confirms a bend that already happened in the closes and does not forecast the next bar.
Settings
- window
- How many recent closes the indicator keeps. At 3 it needs one speed-up in the last three closes, at 4 two in a row, and from 5 up three in a row over the last five closes. Raising it above 5 only delays the first marker.
Pitfalls
- The direction is not checked. A selloff that is slowing fires the same as a rally that is speeding up, so read markers against the trend.
- Above a window of 5 the setting does nothing except delay the first marker, because the test only reads the last five closes. The name suggests a lookback that is not there.
- The $0.001 floor is in dollars, not percent. SPY trades in cents, so any positive speed-up already clears it, and equal changes can pass when float rounding leaves a tiny positive difference.