What Is Relative Strength?

Relative strength is a strategy used in momentum investing and in identifying value stocks. It focuses on investing in stocks or other investments that have performed well relative to the market as a whole or to a relevant benchmark. For example, a relative strength investor might select technology companies that have outperformed the Nasdaq Composite Index, or stocks that are outperforming the S&P 500 index.

Technical analysts use an indicator known as the relative strength index (RSI) to generate overbought or oversold signals.

Understanding Relative Strength

While the goal of value investing is to buy low and sell high, the goal of relative strength investing is to buy high and sell even higher. As such, relative strength investors assume that the trends currently displayed by the market will continue for long enough to allow them to realize a positive return. Any sudden reversal to that trend will lead to negative results.

To identify investment candidates, relative strength investors begin by observing a benchmark such as the Nasdaq Composite Index. They will then look to see which companies within that market have outperformed their peers, either by rising more rapidly than their peers or by falling less rapidly than them.

Because relative strength investing assumes that present trends will continue into the future, it is most effective in stable periods with minimal disruption. By contrast, chaotic periods such as the 2007–2008 financial crisis can be dangerous for relative strength investors because they can lead to sharp reversals of investment trends. In those situations, investor psychology can suddenly reverse, with yesterday’s investment darlings suddenly being shunned.

Although momentum investing is often associated with individual stocks, it can also be applied to whole markets or industry sectors using index funds and exchange traded funds (ETFs). Similarly, investors can make relative strength investments in other asset classes, such as in real estate, using real estate investment trusts (REITs). More exotic instruments, such as commodity futures, options, and other derivative products, can also be used.

Real-World Example of Relative Strength

Harry is a relative strength investor who keeps a close eye on corporate bond prices and the S&P 500. His investment portfolio consists of an S&P 500 index fund and an ETF that tracks the corporate bond market. As a relative strength investor, he periodically increases his allocation toward whichever asset is outperforming at that time. In doing so, he hopes to benefit from the continuing trend of that asset’s outperformance, effectively buying high and selling higher.

In recent months, he has noticed that investors seem to be increasing their portfolio bond allocations at the expense of stocks. This inflow of money into the bond market has been raising bond prices and lowering yields.

Expecting this trend to continue, Harry responds by decreasing his investment in the S&P 500 and increasing his investment in the corporate bond ETF. He hopes to benefit from any ongoing outperformance of bonds relative to stocks.

Relative Strength Index (RSI)

Short-term and technical traders also look at relative strength. In technical analysis, the relative strength index (RSI) is a momentum indicator that measures the magnitude of recent price changes to evaluate overbought or oversold conditions in the price of a stock or other asset. The RSI is displayed as an oscillator (a line graph that moves between two extremes) and can have a reading from 0 to 100. The indicator was originally developed by J. Welles Wilder Jr. and introduced in his seminal 1978 book, “New Concepts in Technical Trading Systems.”

Traditional interpretation and usage of the RSI are that values of 70 or above indicate that a security is becoming overbought or overvalued and may be primed for a trend reversal or corrective pullback in price. An RSI reading of 30 or below indicates an oversold or undervalued condition.

What Is a Technical Indicator?

Technical indicators are heuristic or pattern-based signals produced by the price, volume, and/or open interest of a security or contract used by traders who follow technical analysis.

By analyzing historical data, technical analysts use indicators to predict future price movements. Examples of common technical indicators include the Relative Strength Index (RSI), Money Flow Index (MFI), stochastics, moving average convergence divergence (MACD), and Bollinger Bands®.

How Technical Indicators Work

Technical analysis is a trading discipline employed to evaluate investments and identify trading opportunities by analyzing statistical trends gathered from trading activity, such as price movement and volume. Unlike fundamental analysts, who attempt to evaluate a security’s intrinsic value based on financial or economic data, technical analysts focus on patterns of price movements, trading signals, and various other analytical charting tools to evaluate a security’s strength or weakness.

Technical analysis can be used on any security with historical trading data. This includes stocks, futures, commodities, fixed-income, currencies, and other securities. In this tutorial, we’ll usually analyze stocks in our examples, but keep in mind that these concepts can be applied to any type of security. In fact, technical analysis is far more prevalent in commodities and forex markets, where traders focus on short-term price movements.

Technical indicators, also known as “technicals,” are focused on historical trading data, such as price, volume, and open interest, rather than the fundamentals of a business, such as earnings, revenue, or profit margins. Technical indicators are commonly used by active traders, since they’re designed to analyze short-term price movements, but long-term investors may also use technical indicators to identify entry and exit points.

Types of Indicators

There are two basic types of technical indicators:

1. Overlays: Technical indicators that use the same scale as prices are plotted over the top of the prices on a stock chart. Examples include moving averages and Bollinger Bands®.
2. Oscillators: Technical indicators that oscillate between a local minimum and maximum are plotted above or below a price chart. Examples include the stochastic oscillator, MACD, or RSI.

Traders often use many different technical indicators when analyzing a security. With thousands of different options, traders must choose the indicators that work best for them and familiarize themselves with how they work. Traders may also combine technical indicators with more subjective forms of technical analysis, such as looking at chart patterns, to come up with trade ideas. Technical indicators can also be incorporated into automated trading systems, given their quantitative nature.

Example of Technical Indicators

The following chart shows some of the most common technical indicators, including moving averages, the RSI, and the MACD.

In this example, the 50- and 200-day moving averages are plotted over the top of the prices to show where the current price stands relative to its historical averages. The 50-day moving averages is higher than the 200-day moving average in this case, which suggests that the overall trend has been positive. The RSI above the chart shows the strength of the current trend—a neutral 49.07, in this case. The MACD below the chart shows how the two moving averages have converged or diverged—slightly bearish, in this case.