Direct Answer
A ratio chart plots one asset's price divided by another's over time. A rising line shows the numerator outperforming the denominator, and a falling line shows it underperforming, whatever the absolute price trends. Direction of the ratio line shows relative performance only.
Ratio Chart: Formula, Meaning, Signals, Examples and How to Use It
How Is Ratio Chart Calculated?
A ratio chart plots one asset's price divided by another's over time. A rising line shows the numerator outperforming the denominator, and a falling line shows it underperforming, whatever the absolute price trends.
Formula: Ratio_t = price_A,t / price_B,t; relative change = Ratio_t / Ratio_0 - 1
Inputs:
- Price series for asset A
- Price series for asset B
- Aligned dates
Worked example. A ratio that moves from 120/60 to 135/54 has changed by 25.0%, meaning asset A gained relative to asset B. The inputs are illustrative numbers, not market data.
Reading it. Direction of the ratio line shows relative performance only. It is common to compare a stock to its sector or index, or one asset class to another, to see relative leadership.
Limits. A rising ratio can occur while both assets fall, and ratio charts can mislead if the two series have different dividend or currency treatment. Relative performance is not a forecast.
What is Ratio Chart?
A ratio chart plots one asset's price divided by another's over time. A rising line shows the numerator outperforming the denominator, and a falling line shows it underperforming, whatever the absolute price trends.
How to use Ratio Chart
Direction of the ratio line shows relative performance only. It is common to compare a stock to its sector or index, or one asset class to another, to see relative leadership. A reading alone is never a buy or sell signal; it needs context from price structure, volume, volatility and the broader market regime.
Strengths
- Reading the slope direction alone shows which of two assets has done relatively better over the span, with no separate return calculation.
- The line is dimensionless, so it can be compared across pairs such as sector funds against an index even though their prices differ.
- Reproducible when the formula and data convention are fixed.
Weaknesses and limitations
- Equal steps in the ratio are not equal percentage changes unless the chart uses a log scale, so slopes can mislead the eye.
- The chart reads against one chosen benchmark, so the same asset can look strong against one denominator and weak against another.
- Correlated indicators can create false confidence by repeating the same underlying information.
Editorial and risk note
This page is educational content, not individualized investment advice. It should not imply guaranteed prediction, accuracy or outperformance.
Frequently Asked Questions
Is Ratio Chart a buy or sell signal?
No. Direction of the ratio line shows relative performance only. A rising ratio can occur while both assets fall, and ratio charts can mislead if the two series have different dividend or currency treatment. A trade built on it still needs a trigger, an invalidation rule, a position size and realistic execution assumptions.
What is the best setting for Ratio Chart?
Ratio Chart is computed from price series for asset A; price series for asset B; aligned dates, so the choices that matter are the data convention and the window it is read over. Test those across instruments, regimes and out-of-sample periods instead of fitting one historical winner.
Can Ratio Chart be used by itself?
A rising ratio can occur while both assets fall, and ratio charts can mislead if the two series have different dividend or currency treatment. Relative performance is not a forecast. For that reason it is read next to measures of direction, participation, valuation, liquidity and risk, not alone.
Does Ratio Chart work on every timeframe?
The calculation (Ratio_t = price_A,t / price_B,t; relative change = Ratio_t / Ratio_0 - 1) can be run on any bar size, but behavior is not portable: a reading on a five-minute chart describes a very different market window from the same reading on a daily chart. Validate the exact timeframe before relying on it.
Why does Ratio Chart give false signals?
Equal steps in the ratio are not equal percentage changes unless the chart uses a log scale, so slopes can mislead the eye. The chart reads against one chosen benchmark, so the same asset can look strong against one denominator and weak against another. Lag, noise and regime changes add to this, because market participants react to new information after the reading is calculated.
How should Ratio Chart be backtested?
Rebuild Ratio Chart from price series for asset A using point-in-time data, write the rules before testing, include delisted securities where relevant, model realistic fills and costs, reserve a validation sample and compare with a simpler baseline.