What Is RS Rating for Mutual Funds? The Complete Plain-English Guide

RS (Relative Strength) rating is a 1 to 99 score of how a fund's recent momentum compares to its category peers. RS 90 means the fund has outperformed roughly 90% of similar funds recently. It is the standard tool stock traders use to find leadership - and almost nobody computes it for mutual funds. MF Terminal does, for every fund, every day. This guide explains exactly how it is built, what it can and cannot tell you, and how to use it without fooling yourself.

The question RS answers

Every fund's marketing tells you it is good. Star ratings tell you it was good, averaged over years. Neither answers the question an active investor actually has: of all the funds like this one, which are the strongest right now?

That is a relative question, and it needs a relative answer. A small cap fund returning 8% in three months is unremarkable if every small cap fund returned 10%, and exceptional if the category fell 5%. Raw returns cannot see this; a rank can. RS is that rank, compressed into one number between 1 and 99.

The exact formula

No black box - here is the whole recipe, as our code computes it:

1. For every fund, compute a momentum score: (2 x 3-month return) + (1 x 6-month return) + (1 x 1-year return). The most recent quarter is deliberately double-weighted so the rating notices a fund heating up or cooling down early, while the 6-month and 1-year terms stop one lucky month from dominating.
2. Rank all funds within the same sub-category (small cap against small cap, gilt against gilt) by that score.
3. Convert the rank to a 1 to 99 scale. RS 99: stronger than ~99% of peers. RS 50: dead average. RS 10: nine out of ten peers have done better recently.

A worked example. Suppose three flexi cap funds have (3M, 6M, 1Y) returns of: Fund A (9%, 14%, 22%), Fund B (4%, 16%, 30%), Fund C (2%, 5%, 8%). Their momentum scores are A: 2(9)+14+22 = 54, B: 2(4)+16+30 = 54, C: 2(2)+5+8 = 17. A and B tie on the score despite very different journeys - A is accelerating now, B built its number earlier in the year - while C trails badly. The percentile rank across the whole category then turns those scores into RS ratings.

This is the same construction Investor's Business Daily popularised for US stocks decades ago. It has survived because it captures something real about markets, which brings us to the honest part.

Why momentum contains information at all

It feels wrong that past strength should predict anything - and yet momentum is one of the most persistently documented effects in market history, across countries, decades and asset classes. Winners over the past 3 to 12 months have tended, on average, to keep winning over the following months. Not always, not forever, and with brutal occasional reversals - but often enough that ignoring it means ignoring data.

Why would it exist? The common explanations are human: information spreads gradually, investors anchor on old prices and under-react to change, and money chases performance with a lag. A fund version adds another layer: fund momentum often reflects a style or sector tide - when small caps lead the market for a year, most small cap funds print high market RS together, because the rating is partly measuring the category's tide, not just each captain.

That last point is the single most useful thing to understand about RS, so it gets its own section.

Fund skill or category tide? Category RS vs Market RS

We compute RS two ways precisely to separate these:

• Category RS ranks a fund against its own kind. It strips the tide out: every small cap fund is riding the same small cap wave, so a high category RS means this fund is beating its true peers - the closest thing to a skill-and-positioning signal a rating can give.
• Market RS ranks the same momentum score against the entire growth universe: equity, hybrid, gold, international, index funds together. It measures the tide and the swimmer at once. A category-RS-99 debt fund will show a modest Market RS in an equity bull market, because it is not in that race.

Reading them together is where the insight lives. High category RS + high market RS: a strong fund in a strong category - full sail. High category RS + low market RS: the best swimmer in an out-of-favour pool - worth watching for when its category turns. Low category RS + high market RS: a weak fund being carried by a hot category - the tide is doing the work, and tides go out.

The RS line and 52-week RS highs

The rating is a snapshot; the RS line on our charts is the movie. It divides the fund's NAV by its benchmark index and rebases to 100: rising line, fund beating its index; falling line, lagging. It makes multi-month leadership changes visible at a glance in a way two return numbers never can.

When the RS line reaches its highest level in 52 weeks we flag a new RS high. Traders watch these closely for one reason: a fund making new relative highs against its benchmark is, by definition, doing something its index cannot explain - and new RS highs have a habit of clustering at the start of long leadership runs. The What Changed tab tracks every fresh RS high across the universe daily.

How to read the number

Two properties to internalise. First, RS is fast on purpose - it can move meaningfully in weeks, because that is its job. A fund's RS collapsing from 85 to 40 is the rating working, not breaking: it is telling you leadership changed. Second, RS is zero-sum within a category: for every fund at 90 there must be funds at 10. A falling RS does not necessarily mean the fund fell; it can mean peers accelerated.

RS and King Score: the two-clock system

RS deliberately measures a different clock from our King Score, which grades long-term quality (returns, consistency, drawdowns, Sharpe over years). The grid of the two is the fastest read of any fund:

Every fund page shows both numbers side by side so you can place the fund on this grid in two seconds. The combinations are more informative than either number alone: a King-90 fund at RS 25 is a very different research question ("is this temporary style rotation or decay?") from a King-30 fund at RS 95 ("is this the start of something or a sugar rush?").

The honest pitfalls

RS is a sharp tool, and sharp tools cut careless users. The failure modes, plainly:

1. Mean reversion at the extremes. The hottest funds eventually cool; buying RS 99 at the top of a sector mania is momentum's classic trap. The rating tells you what is leading, not how long the lead lasts.
2. Chasing after the move. By the time a fund reaches RS 95, much of the run that produced the rating has already happened. Momentum investors make peace with never buying bottoms; momentum tourists buy tops and quit.
3. Churn costs. Acting on every RS wiggle means exit loads and taxes. Our no-exit-load fund list exists partly for this reason, and our backtester models load costs precisely because switching is never free.
4. Sector funds amplify everything. A sectoral fund's RS is mostly its sector's story. The ratings work; just know what they are measuring - see the momentum check on any ranking page for how hot each category currently runs.

None of these make RS useless; they make it a component. The investors who use RS well use it as a filter and a flag - a reason to look closer - not as an autopilot.

Where to see it

Every fund page shows the fund's category RS and Market RS with its King Score. Every ranking page includes a live momentum check - how many funds in the category rate RS 90+ and which fund leads. And the free terminal lets you screen and sort all 8,000+ schemes by RS, chart any fund's RS line against its benchmark, and track every new 52-week RS high as it prints.

FAQ

How often does RS update? Every day, with fresh NAVs. It is a daily snapshot of a rolling 3-to-12-month window.

Is RS 95 a buy signal? No. It is a fact about recent relative performance. Whether that fact matters for you depends on the fund's long-term record, your horizon, and costs - and this site never gives buy or sell advice.

Why did a fund's RS fall when its NAV went up? Because RS is relative. If the fund gained 5% while peers gained 12%, its rank fell. RS measures the race, not the runner's speedometer.

Does RS mean anything for debt funds? Within very short-duration categories the spread between funds is tiny, so RS mostly amplifies noise - treat it lightly there. It matters most where dispersion is wide: equity, sectoral and hybrid categories.

How is RS different from a star rating? Star ratings blend years of risk-adjusted history into a slow-moving grade - closer in spirit to our King Score. RS measures the last 3 to 12 months against peers and moves fast. They answer different questions; the mistake is using either to answer the other's question.

MF Terminal is descriptive research and education, not investment advice. All figures are pre-tax. Past performance - including recent relative strength - does not guarantee future returns. Full formulas: our public methodology.