By Nummius · October 31, 2026
A relative strength (RS) line shows one stock’s performance against one benchmark over time. A relative rotation graph (RRG) shows many securities at once, plotting their relative strength and the momentum of that strength on one chart. And RSI, despite the name, isn’t relative strength at all: it measures a stock’s momentum against its own past prices. Use the RRG to scan a group, the RS line to study one name, and RSI for momentum timing.
The three, side by side
| Relative strength line | Relative rotation graph | RSI | |
|---|---|---|---|
| Compares | One security vs a benchmark | Many securities vs one benchmark | A security vs its own recent price changes |
| Shows | The ratio over time | Relative strength (x) and its momentum (y) now, plus a tail | Momentum on a 0–100 scale |
| Best for | Studying one stock or sector in depth | Scanning a group: sectors, stocks in a sector | Timing pullbacks and spotting fading momentum |
| Answers | “Is this beating the market?” | “Which of these are gaining or losing leadership?” | “Is buying pressure strong or weakening?” |
The relative strength line
It’s simple: divide the stock’s price by the benchmark’s price and plot the result.
- Rising line: the stock is outperforming.
- Falling line: it’s underperforming.
- RS line at a new high before price: a well-known sign of leadership, often seen before breakouts.
Strengths: easy to read; works for any pair; long history visible. Limits: one pair at a time; doesn’t show whether outperformance is speeding up or slowing down unless you study the slope.
The relative rotation graph
An RRG takes the RS idea and adds momentum:
- Horizontal axis: relative strength, normalized so 100 is the benchmark.
- Vertical axis: momentum of that relative strength.
- Four quadrants: Leading, Weakening, Lagging, Improving.
- Tails: recent path, so you see direction.
Strengths: scans a whole group at a glance; shows turns early, as things move from Lagging to Improving or from Leading to Weakening. Limits: doesn’t show absolute price trend; tails on short timeframes can be noisy. Read our guide to reading an RRG.
RSI is not relative strength
The Relative Strength Index compares average gains to average losses over recent periods for a single security. It doesn’t involve a benchmark. A stock can have a high RSI while underperforming the market, or a low RSI while outperforming. It’s a momentum tool, covered in our swing trading indicators guide.
How to use them together
- RRG: find sectors in Leading or moving from Improving into Leading.
- RRG again: plot stocks within those sectors against the sector ETF.
- RS line: check the best candidates. Is the line making new highs?
- Price chart and RSI: time the entry on a pullback or breakout, with RSI holding above about 40–50 in an uptrend.
- Stop and size: set the stop on the price chart and size from it.
This is the core of an RRG trading strategy.
Which one should you use?
- Scanning many names: RRG.
- Confirming one name: RS line.
- Timing: price action, with RSI as context.
In Nummius
Nummius Markets includes relative rotation graphs for all 11 sector ETFs against SPY, with playback so you can see how rotation developed. The screener filters on RSI, ATR, volume and momentum, and the chart has the usual indicators. Core has a 14-day free trial; see pricing.
RRG® and Relative Rotation Graphs® are registered trademarks of RRG Research. Nummius is not affiliated with RRG Research.
Frequently asked questions
Is RSI the same as relative strength?
No. RSI measures a security’s momentum against its own past prices. Relative strength compares a security’s performance to a benchmark.
What does a relative rotation graph add to a relative strength line?
It shows many securities at once and adds the momentum of relative strength, so you can see which are gaining or losing leadership and in which direction they’re moving.
What benchmark should I use for relative strength?
For sectors, a broad index like SPY. For individual stocks, their sector ETF or the index.
This article is for educational purposes only and is not financial advice. Trading involves risk, including the loss of money. Past performance, backtests and practice results do not guarantee future results.