Economic calendar · Beginner

Understanding Impact Ratings

A star count tells you which releases have the capacity to move price. It cannot tell you whether this particular one will.

Last reviewed 15 September 2026 by the MarketPro research desk · Editorial policy

In short

An impact rating estimates how much volatility a scheduled release has produced historically, usually shown as low, medium or high. It is a filter for deciding what deserves attention, not a prediction. A high-impact event that matches expectations can move price barely at all, and a medium-impact release can move it sharply when it speaks directly to the current policy question.

What to remember

The rating is an average of a fat-tailed distribution, which is why individual releases routinely land nowhere near it.
A three-star rate decision priced at 96% probability has almost no room left to surprise. The capacity to move is whatever the market has not already discounted.
Agreement among forecasters is invisible on the rating. A contested number and a settled one can carry the same three stars and behave nothing alike.
Halving a 0.2 lot position to 0.1 lot turns a 60 pip overshoot from a $120 loss into a $60 one, and halves the upside too.

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An impact rating is the calendar's estimate of how much volatility a release has tended to produce in the past, shown as low, medium and high or as one to three stars. It is a sorting tool for your attention. It is not a forecast of the next release, and the gap between those two things is where people get caught.

The two-star print that moved 90 pips

Take a retail sales release carrying a medium rating. Consensus is +0.3% month on month, the actual prints at -0.7%, and it lands two weeks after a central bank that spent its entire press conference saying its next move depends on incoming data. That combination produced a 90 pip move on a major pair inside twenty minutes, because the release stopped being about retail sales and became about the next rate decision.

Now take the opposite case. A rate decision carrying three stars, where the interest rate futures market already assigns 96% probability to a hold, delivers exactly that hold with a statement barely changed from the previous one. Total range on the pair: 12 pips. The three-star event was, on the day, a non-event.

Neither outcome means the rating was wrong. It means the rating is an average drawn from a distribution with very fat tails, and an average is a poor description of a distribution like that. What the star count tells you is which releases have the capacity to move price. It cannot tell you whether this particular one will.

What sits in each tier

Tier	Typical entries	What it should change
Low	Regional surveys, second-tier sentiment indices, minor trade figures, most speeches by non-voting officials	Nothing. Read it later if at all.
Medium	Retail sales, industrial production, final PMI revisions, housing data, weekly jobless claims	Worth knowing the time. Can move sharply when it speaks to the current policy question.
High	Rate decisions and press conferences, CPI, the monthly employment report, GDP first estimates, flash PMIs	An explicit decision on size, and on whether to be in the market at all.

Ratings also differ between calendar providers, because each one weights its own history differently. If you switch tools you will find releases that move up or down a tier. That is a useful reminder that the number is an editorial judgement, not a measured constant.

One more asymmetry is worth knowing. Ratings are assigned per release, but volatility arrives per cluster. A Thursday with a two-star jobless claims number at 13:30 and a three-star central bank speech at 13:45 is not two separate events, it is one forty-five minute window in which liquidity is thin throughout. Calendars display them as separate rows because that is how the data is published, and the trap is reading the low-rated row as though the high-rated one were not sitting fifteen minutes behind it.

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Three things the rating cannot see

What is already in the price. A release is only capable of moving the market by the amount that is not yet discounted. The 96% priced rate hold above had almost no room left to surprise.
The context it lands in. The same PMI number matters enormously in a week when the market is arguing about recession and matters barely at all in a quiet quarter. Ratings are static; the policy debate is not.
How tightly forecasters agree. The rating is set on the release, not on the state of opinion about it. A number the panel is split over and a number every economist has pinned to within a tenth of a point can carry the same three stars, and a print half a point from consensus is a different event in each case.

From a star count to a lot size

The rating is only useful if it changes something you do. The most direct translation is into position size, and the arithmetic is simple. Suppose your normal risk is 1% of a $5,000 account, so $50 per trade, and your stop on a EUR/USD setup is 25 pips away. That is roughly a 0.2 lot position at $2 per pip. If a three-star release lands inside your expected holding period, halving to 0.1 lot means the same 25 pip stop now costs $25 instead of $50, and a 60 pip overshoot through your stop costs $60 rather than $120.

You have not removed the risk. You have halved the size of a loss you cannot forecast, and you have also halved the win if the move goes your way. That is the trade, stated honestly. The position size calculator makes the adjustment a ten-second change, which matters because a decision that takes effort will not be made consistently.

A sanity check before you trust the marker

Before an event you have flagged as high impact, look at the last three or four instances of the same release on a chart and measure the range in the thirty minutes afterwards. Compare it to the average true range of the hour you normally trade. If the post-release range is two or three times your usual stop distance, your stop is not protecting you during that window, it is simply a price at which you will be removed. A useful cross-check is how forex prices move, which sets out why rate expectations sit underneath most of these reactions, and the pip calculator for converting the measured range into money on your own account size.

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Written and reviewed by the MarketPro research desk

MarketPro is a trading-signal and trading-education app operated by Harajuku Holdings LTD (Cyprus). Our signal desk publishes and tracks every trade idea in-app, and every page here is checked against the app's live behaviour before publishing. Last reviewed 15 September 2026. How we produce signals and content · About MarketPro

FAQ

Understanding Impact Ratings: questions

Are economic calendar impact ratings the same on every website?

No. Each provider weights its own history and editorial judgement differently, so the same release can carry two stars on one calendar and three on another. Treat the rating as a rough sort rather than a standardised measure, and check the actual price behaviour of the last few instances of a release if it matters to a position you hold.

Why did a high-impact release barely move the market?

Because the outcome was already priced. If interest rate futures assign a 96% probability to a hold and the central bank holds, there is almost nothing left to discount, and the reaction can be a dozen pips. Movement comes from surprise, so an event can be enormously important and still produce a flat chart when it delivers exactly what everyone expected.

Should I avoid trading during all high-impact news?

That is one defensible policy, but it is not the only one. Holding through a release at reduced size is also defensible if the plausible range is survivable at that size. What is hard to defend is carrying full size through a three-star event without having made a deliberate decision about it, because then the outcome is an accident rather than a choice.

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