Indicators
Parabolic SAR (Stop and Reverse)
A dot that trails price and accelerates as a trend extends, then flips to the other side the instant price stops it out. It is a trailing stop mechanism first, a signal second.
Adjust the acceleration, watch every real flip get booked as a trade
Every dot below is computed bar by bar with the real Wilder SAR formula, no shortcuts. Drag the acceleration sliders and the whole dot path recomputes and redraws instantly against the same price. Every time the dots flip sides, that's logged as a trade in the ledger, entered and exited mechanically at the flip price. Switch the regime toggle to rerun the identical AF settings against a trending path or a choppy, range-bound one, and watch what that does to the ledger.
Press play or step to walk through the bars and build the SAR live.
- Flips (trades) will appear here as they happen.
How it works
- The dot moves toward price by a fraction of the distance each bar. SAR(next) = SAR(current) + AF × (EP − SAR(current)), where EP is the extreme point, the highest high reached so far in an uptrend or the lowest low in a downtrend.
- AF starts small and grows with the trend, capped at a maximum. Every time price sets a fresh extreme, AF increases by the step amount (0.02 by default) up to the max (0.20 by default). A trend that keeps making new highs pulls the dot toward price faster and faster.
- The dot can never move into the prior one or two bars' range. In an uptrend, SAR is capped at the lower of the last two bars' lows, so the trailing stop only ever tightens, it never jumps ahead of price and gets randomly stopped out on ordinary noise.
- A flip happens the moment price actually crosses the dot. If a bar's low trades through the SAR in an uptrend, the trend flips to down, the new SAR becomes the old extreme point, and AF resets all the way back to its starting value. The mirror image happens on the downside.
Where this breaks
In a ranging market, SAR chops you from one small loss to the next
Parabolic SAR is built entirely around the assumption that price is trending, its whole purpose is trailing a stop behind a move that's actually going somewhere. In a genuinely range-bound market, price oscillates back and forth across a fairly narrow band, which means the dot keeps flipping sides every few bars, each flip getting stopped out again almost immediately by the next swing back the other way. Every one of those flips is mechanically correct by the formula, the dot is doing exactly what it's supposed to do, and every one of them still loses a little money to the whipsaw. Toggle the regime switch above to choppy and rerun the exact same acceleration settings that looked fine in a trend, the flip count climbs and the ledger fills with small losses stacked back to back, which is the honest, textbook failure mode of this indicator, not a tuning mistake.