Ch 6 · Indicator
Trend Lagging

Parabolic SAR

Dots plotted above or below price that accelerate toward it as a trend persists. When price crosses the dots, the trend has flipped.

Formula

SAR(t+1) = SAR(t) + AF · (EP − SAR(t))
AF starts at 0.02, +0.02 per new extreme, capped at 0.20

What it's for

Trailing stop in trending markets, mechanical flip signals on scalping timeframes.

When it fails

Terrible in sideways markets — near-constant flips. Fixed acceleration doesn't adapt well to volatility regimes.

On the chart

Nifty 50 daily bars with Parabolic SAR pre-loaded:

Where it's used on this site

1 strategy uses Parabolic SAR: