Relative Strength

What Is Relative Strength?

Relative strength measures how one asset performs compared to another, typically a benchmark index like the S&P 500. It is calculated as a simple ratio: the price of the asset divided by the price of the benchmark. A rising ratio means the asset is outperforming; a falling ratio means it is underperforming. This concept should not be confused with the Relative Strength Index (RSI), which is a completely different indicator.

Relative strength analysis helps traders answer a fundamental question: even if a stock is going up, is it going up faster or slower than the overall market? A stock rising 5% while the market rises 10% has weak relative strength despite its positive absolute return.

How Traders Use Relative Strength

Stock selection is the primary application. Traders screen for stocks showing strong relative strength over multiple timeframes (one month, three months, six months). Stocks that consistently outperform the market tend to continue doing so, a well-documented phenomenon in academic finance research.

Sector rotation analysis uses relative strength to identify which sectors are leading and which are lagging. When the relative strength of the technology sector versus the S&P 500 breaks out to new highs, it signals that technology stocks are likely to continue leading. Shifting allocation toward leading sectors and away from lagging ones is a core institutional strategy.

Relative strength rankings assign each stock a percentile score based on its performance relative to all other stocks. A stock with a relative strength rank of 90 has outperformed 90% of all stocks over the measured period. Many momentum-based strategies focus exclusively on stocks in the top decile of relative strength.

Relative Strength in Different Market Environments

During bull markets, relative strength helps identify the strongest stocks within a rising tide. During bear markets, it helps identify relative safe havens or stocks that may lead the next recovery. Stocks that decline less than the market during corrections often become the first leaders when the market rebounds.

The persistence of relative strength trends makes the indicator valuable for position traders and investors, though it can also be applied on shorter timeframes for swing and day trading purposes.