Laguerre RSI indicator: a faster RSI with one dial

Your 14-period RSI finally crosses back above 30, and by then price is already halfway to the level you wanted to buy near. The Laguerre RSI indicator is John Ehlers’ answer to that delay. It measures the same up-versus-down balance as RSI, but through a four-stage filter tuned by a single setting called gamma, so it turns within a few bars instead of a dozen.

By the end you will know what gamma really controls, how to read a line that sits flat at its ceiling, and where this oscillator fits next to the RSI you already use.

What is the Laguerre RSI indicator?

The Laguerre RSI is an oscillator from 0 to 1 that tracks whether recent movement has been mostly up or mostly down, like Welles Wilder’s RSI, but with a much shorter effective memory. John Ehlers described it in his paper “Time Warp: Without Space Travel” and again in his 2004 book Cybernetic Analysis for Stocks and Futures.

The name comes from the Laguerre filter, a signal-processing tool named after the French mathematician Edmond Laguerre. Ehlers’ point was simple. A long averaging window is not the only way to get a smooth line. You can get a similar smoothness from a short chain of filters that each bend time a little.

Wilder’s original RSI, published in 1978 and summarised well in Investopedia’s RSI reference, averages gains and losses over a fixed lookback, usually 14 bars. That lookback is where the delay lives. Laguerre RSI drops the lookback entirely and replaces it with gamma.

How does the four-stage filter work?

Price passes through four smoothing stages in a row, each one a slightly delayed and softened copy of the stage before it. The indicator then compares neighbouring stages. Each time a stage sits above the next one, it counts as a rise; each time it sits below, it counts as a fall. The reading is the share of rises in the total.

Think of four runners on a track, each following the one in front with a short delay. If they are strung out in order heading uphill, every gap points up and the reading is 1. If they bunch and cross, the reading lands somewhere in the middle.

Look at how long the green line sits on the ceiling. A classic RSI would have wandered around 70 during the same rally; the Laguerre version pins at 1.0 until the ordering breaks, and the first real signal is the close back under 0.8.

What does gamma change, and how should you set it?

Gamma decides how much each stage leans on its own last value versus the new price. Low gamma is fast and noisy; high gamma is slow and smooth. Ehlers used 0.5 in his example, and most builds ship with a default in the middle of the range. There is no correct number, only one that fits the pair and timeframe you trade.

The practical way to tune it is to count, not to guess. Put two copies on one chart with different gamma values. Scroll back through a trending week and a ranging week, and tally how many 0.2 and 0.8 crosses each copy produced that you would have wanted to take. Move gamma in small steps and stop when the count of unwanted crosses stops falling faster than the useful ones.

The chart makes one point: decide the market type first, then decide what a cross means. The same 0.2 cross is a pullback entry in a trend and noise in a tight range.

How is it different from RSI and Stochastic RSI?

All three measure momentum on a bounded scale, but they spend their smoothing differently. Classic RSI averages over a window. Stochastic RSI runs a stochastic on top of RSI, which makes it fast but jumpy. Laguerre RSI gets its speed from the filter chain, so it turns early without the extra layer of math.

If you want the slower, more conventional read, our walkthrough on tuning the period and levels of a standard RSI covers it. If what you like here is Ehlers’ habit of sharpening turns, his Fisher Transform attacks the same goal from a statistical angle.

Does the Laguerre RSI repaint?

A standard build does not rewrite closed bars. Each value is built from the filter’s previous state and the latest close, so once a candle finishes, its reading is fixed. The live candle is a different story: it moves with every tick and can poke above 0.8 mid-bar, then close back below it.

Multi-timeframe copies are the real risk. A version that projects a four-hour reading onto a fifteen-minute chart will keep reshaping the last few lower-timeframe values until the four-hour candle closes. If a backtest looks too clean, that is the first place to check. The broader method is in our guide to spotting a genuinely non-repainting indicator.

Where RelicusRoad Pro fits

The Laguerre RSI tells you when a pullback has probably run its course. It does not tell you whether the bigger move is worth joining, or where your stop belongs. RelicusRoad Pro handles that side: its structure levels and confirmations settle at the candle close and stay put afterward, on MT4, MT5, and TradingView alike. A fast oscillator gives you timing. A fixed map of where price has reacted gives that timing somewhere sensible to happen, and neither one replaces sizing each position so a loss stays small.

Frequently asked questions

What is the Laguerre RSI indicator?

The Laguerre RSI is an oscillator built by John Ehlers that measures the same thing as a classic RSI, the balance of upward against downward movement, but gets there through a four-stage Laguerre filter instead of a long averaging window. The output runs from 0 to 1. Because the filter squeezes the useful history into a handful of bars, the line turns much sooner than a 14-period RSI and needs far less data to warm up. Versions exist for MT4, MT5, and TradingView, usually under the name Laguerre RSI or LRSI.

What does gamma do in the Laguerre RSI?

Gamma is the damping factor, a number between 0 and 1 that sets how strongly each filter stage holds on to its own previous value. A low gamma lets new prices through almost untouched, so the line is fast and noisy. A high gamma leans on the past, so the line is smoother and later. Ehlers used 0.5 as his example value. Most traders test somewhere in the middle of the range and move it in small steps while watching how many crosses they get.

Why does the Laguerre RSI stay flat at 1 or 0?

When price moves in one direction for several bars, all four filter stages line up in order, so every comparison between them counts as a rise, or every one counts as a fall. The ratio then hits its ceiling of 1 or its floor of 0 and stays there until the order breaks. A flat line at the top is the market saying the push is intact. Selling it because it looks overbought misreads what the line is telling you.

Does the Laguerre RSI repaint?

A standard build does not rewrite finished bars. Each value comes from the filter’s previous state plus the new close, so once a candle closes, its reading is fixed. The live candle is different, because its value moves with every tick and can cross 0.2 or 0.8 and then retreat before the close. Multi-timeframe versions that pull a higher timeframe onto a lower chart can shift past values until the bigger candle completes. Confirm any cross on a closed bar.

Is the Laguerre RSI better than a standard RSI?

It is faster, not better. The Laguerre version turns earlier and spends more time at its extremes, which suits short-term timing inside a trend you have already identified. The classic 14-period RSI is slower but gives more readable divergences and a long record of shared conventions around the 30 and 70 levels. Pick by job: Laguerre RSI for pullback timing, classic RSI for broader momentum and divergence work.

Want your fast oscillator’s timing tied to levels that don’t move after the close? See how RelicusRoad Pro locks its reads at the candle close.

Written for RelicusRoad by RelicusDigital.com.