Relative Strength (RS) is the most widely used momentum measure in trend-following trading. The first thing to clear up is that it is an entirely different concept from the similarly named RSI (Relative Strength Index). Where RSI is an oscillator that reads whether a single stock's price is overbought or oversold on a 0–100 scale, the RS discussed here is a relative measure that expresses how much stronger a stock is compared with the entire market as a percentile rank.
RS Isn't "How Much It Rose" but "Is It Stronger Than the Rest"
Suppose a stock rose 10% over a month. That number alone can't tell you whether it's strong. If the whole market rose 15% in the same period, the stock is actually a laggard; if it rose 10% while the market fell 5%, it's a remarkable leader. RS converts exactly this "relative position versus everyone else" into a rating from 1 to 99. An RS of 99 means the top 1% by momentum across the whole market — the strongest stocks.
Weighted RS Puts More Weight on Recent Periods
Trend Screener and other classic trend-following tools use a weighted average that emphasizes recent periods rather than a simple one-year return. Trend Screener gives 40% to the 3-month window, 30% to 1 month, 20% to 6 months and 10% to 1 week.
The reason is clear: a stock that was strong a year ago but has since lost steam should not get the same score as one that has broken out explosively over the last three months. By placing the most weight on the nearest quarter and confirming with 1 month and 1 week, you can quickly catch the next generation of leaders — the ones that make new highs first as the market bottoms and turns. Weight a distant window like 12 months instead, and last year's leaders stay near the top for months after they have topped out.
The RS Line Leads — New Highs Before Price
The most powerful practical use of RS is catching the RS line (stock price ÷ index) making a new high before the price does. William O'Neil singled out stocks whose RS line breaks to new highs while the price is still inside its base as the most promising breakout candidates. A stock that falls less during corrections and recovers first — in other words, one under relative accumulation — leaves that footprint on the RS line before the price chart shows it. The reverse also matters: if the price makes a new high but the RS line fails to clear its prior peak, the advance is nothing special versus the market — a warning sign.
Reading RS Alongside Volume and Industry
You don't trade on RS alone. In practice, overlapping three things raises your confidence.
- Volume: a high-RS stock that trades heavy volume on up days is likely under accumulation by institutions. Conversely, an RS that rose without volume is weak on durability.
- Industry strength: a trend lasts longest when a strong stock sits inside a strong industry. It's efficient to check the top groups by Industry Score first in Trend Screener's Industry Rankings, then pick the high-RS names within them.
- Trend structure: even with a high RS, if the moving averages aren't aligned it may be a temporary bounce. Only a stock that also passes all 8 Trend Template conditions (8/8) can be read as being in a Stage 2 uptrend.
Case in Point — Leadership Changes Show Up in RS First
Nvidia (NVDA) became famous for its explosive gap-up in May 2023, but from an RS perspective the more important fact came months earlier: through January–April 2023, while the broad market was still finding its direction, Nvidia's RS was already parked in the top ranks. The stocks that strengthen first while the index hesitates tend to lead the next phase — exactly as the principle says. The same mechanism appears at the group level in every market: when one year's dominant theme gives way to the next, the change announces itself as turnover in the top of the RS rankings long before it becomes a headline. That is why a screener that records the ranking every single day is worth keeping open.
Limits and Common Misreadings of RS
- RS 99 does not mean "overbought." RS is a rank, not an overheating gauge like RSI or extension. Genuine leaders hold an RS of 95–99 for the entire length of their advance. A high RS is a reason for attention, not a reason to sell.
- Crash markets distort it. When everything falls, the names that merely "fell less" — defensives — float to the top of the RS table. Their high RS marks relative resilience, not a buy signal. This is why absolute trend conditions like the 8 criteria must be read together.
- Thin stocks are noisy. In low-liquidity names, small money moves the rank around. Set a floor in the volume filter to screen the noise out.
- A rolling-over RS is a warning. If a holding's RS slides from the 90s into the 70s, it is losing strength versus the market even if the price still holds up. Time to tighten stops and trailing rules.
Narrowing It Down at Once with the Leaders Filter
Cross-checking these three by hand every time is tedious, so the filter bar lets you stack two of them — raise the RS filter to 90 (or 80/70) and check the top-ranked industries in the industry filter, and you are left with stocks at RS 90+ inside strong groups. The industry list is sorted by the same Industry Score (0–100) ranking as the Rankings page, so you can pick from the top down. It's William O'Neil's "Leader or Laggard" principle applied in two clicks.
Frequently Asked Questions
What RS level counts as a leader?
The Trend Template's floor is 70, but both Minervini and O'Neil advised focusing on 80–90+ in practice; Trend Screener's leader definition uses 90, and the RS filter's top preset is 90, for the same reason. Treat the number as a starting point, though — an RS-92 stock in a strong group with a tight base can be a better candidate than an RS-97 stock already in a climax run.
Should I sell when a holding's RS drops?
A falling RS by itself is a caution, not a sell order. Leaders routinely give up a few ranking spots during rotations. The natural sequence is: take the warning → tighten your stop and trailing rules → act when a price-based level (support, your stop) actually breaks. But if RS keeps sliding for weeks, money is migrating elsewhere — worth considering a switch into a stronger name.
Can I use RSI together with RS?
You can, as long as the roles stay separate: RS answers "which stocks are strong" (selection), RSI hints at "short-term stretched or washed-out" (timing aid). The classic mistake is selling a true leader because RSI says overbought — leaders stay overbought for months. Select with RS and the 8 conditions; time entries with price structure (pivots, support) and volume.
How is RS handled for recent IPOs?
Names without history covering the longest window (6 months) are approximated over the window that exists, or excluded in some tools. Since many of history's biggest winners were young stocks within a year or two of listing, judge recent IPOs less by the RS number and more by the structure — does it build a sound first base and break to new highs?