Relative Strength Rank: Why RS 90+ Matters for Swing Traders

What is Relative Strength (RS) Rank?

Relative Strength (RS) rank measures a stock's price performance relative to all other stocks over a defined lookback period — typically 12 months (with the most recent quarter weighted more heavily in some versions).

An RS rank of 90 means the stock has outperformed 90% of all stocks in the universe over that period. An RS rank of 99 means it's in the top 1%.

This metric was popularised by William O'Neil and Investor's Business Daily (IBD), where it was called the RS Rating. Mark Minervini and others have validated it empirically: stocks with RS rank above 80–90 at the time of a major breakout have historically produced better returns than lower-ranked stocks. O'Neil's research on 600+ of the biggest stock market winners from 1953–2008 found that their median RS rank was 87 before the start of their major price advances (*How to Make Money in Stocks*, 4th ed., 2009).

Why High RS Rank Matters

The intuition is straightforward: stocks that are already outperforming tend to keep outperforming — at least in the short to medium term. This is the momentum premium, one of the most well-documented anomalies in academic finance.

For swing traders specifically:

• High RS stocks are already being accumulated by institutions — you're following smart money
• They tend to hold up better in weak markets (relative strength)
• They're more likely to be leaders in the next bull cycle, not laggards catching up

O'Neil's research on the biggest market winners found that most had RS ranks above 90 *before* their biggest price advances began. Jegadeesh and Titman's seminal 1993 paper "Returns to Buying Winners and Selling Losers" demonstrated that momentum-based strategies (buying high-RS stocks) generated excess returns of 12.01% per year over their study period — one of the most well-replicated findings in financial economics.

RS Rank vs RS Line

These are two different but related concepts that are often confused:

RS Rank is a percentile score (0–99) comparing a stock to all other stocks. It's a snapshot.

RS Line is a ratio line showing the stock's price divided by the S&P 500 (or another benchmark) over time. It shows whether the stock is *strengthening or weakening* relative to the market. A rising RS line is bullish; a falling RS line is bearish even if the stock's price is rising.

EasySwing tracks both. The RS rank is shown as a badge (e.g., "RS 91") in scan results. A rising RS line trend is factored into the momentum score.

The RS 90 Threshold in Practice

Why 90 specifically? Research and practitioner experience suggest:

• Stocks in the 80–90 range are "good" but not exceptional
• Stocks in the 90–95 range are in the top tier of market leaders
• Stocks in the 95–99 range are the current cycle leaders — these produce the biggest wins but also carry more risk of sharp reversals

For a balanced swing trading approach, EasySwing uses RS ≥ 90 as a filter for high-conviction setups and RS ≥ 70 for a broader scan. The RS rank is prominently displayed in the scanner results as a coloured badge:

• Amber (RS 80–89): Strong but watch for improvement
• Green (RS 90+): Market leader territory

RS Rank at the Pivot: The "RS Before the Breakout" Concept

One nuance practitioners swear by: the RS line making a new high before or at the same time as the price breakout is a strong confirmation signal. This means the stock is showing relative strength *before* the obvious price breakout — a sign of institutional buying.

EasySwing's breakout alert checks whether the RS line is at a 52-week high (or trending toward one) when a stock approaches its pivot point.

RS Rank in Context: Avoid RS Fade Traps

High RS rank alone isn't sufficient. Watch out for:

• RS fade: A stock that had RS 95 six months ago but has drifted to RS 60 — it's losing momentum relative to the market
• Sector concentration: Many high-RS stocks in a narrow sector can indicate a crowded trade
• Overextension: A stock with RS 99 that's up 300% from its base may have limited near-term upside

EasySwing combines RS rank with Stage 2 analysis, VCP pattern detection, and EPS quality to reduce these false signals. A stock needs to satisfy multiple criteria before it's surfaced as a high-confidence setup.

How EasySwing Calculates RS Rank

EasySwing calculates RS rank using daily closing price data from Alpaca for all stocks in its universe (2,000+ equities). The calculation:

1. For each stock, compute the 12-month price performance (with the most recent 3 months weighted at 2×) 2. Rank all stocks from highest to lowest performance 3. Convert to a percentile (0–99) — rank 99 = top 1%, rank 0 = bottom 1%

The calculation runs as part of the enrichment pipeline that refreshes twice daily (midday and after close), so RS ranks reflect the latest daily price action.

Practical Checklist for Using RS Rank in Trade Selection

• ✅ RS rank ≥ 90 for high-conviction entries; ≥ 70 for broader scan
• ✅ RS line trending up over the past 3 months (not fading)
• ✅ RS line at or near a 52-week high at time of breakout
• ✅ RS rank has been stable or rising for the past 4–8 weeks (not a recent spike)
• ❌ Avoid stocks where RS rank has dropped 10+ points in the past month
• ❌ Avoid entries where RS line is below its 50-day average

*EasySwing displays RS rank in real-time for every stock in the scanner. Combine RS 90+ with Stage 2 analysis and VCP pattern detection for the highest-conviction setups. Learn how to size your positions with R-multiples. Scan results are for informational purposes only. See our Risk Disclaimer.*