Open two currency strength meters side by side and there is a fair chance one shows the euro as the strongest currency of the day while the other has it mid table. Both are calculating correctly. They are calculating different things, because the inputs a strength meter needs are not standardised: the lookback period, the pair universe, the weighting and the normalisation are all author choices.
That does not make the tool useless. It makes it a summary rather than a signal, and the distinction changes how you should use it.
How the number is produced
Take the eight majors, USD, EUR, GBP, JPY, CHF, CAD, AUD and NZD. Every one of them trades against the other seven, giving 28 pairs. For each currency, the meter measures percentage change across every pair it appears in over some lookback, flips the sign where the currency is the quote rather than the base, and averages. Normalise the eight results onto a scale and you have the bar chart.
The arithmetic is uncontroversial. Every design choice around it is not.
The lookback dominates everything. A meter set to one hour and a meter set to one day will frequently rank currencies in opposite order, and neither is wrong. Weighting matters next: an unweighted average treats NZDCAD as equally informative as EURUSD, which is hard to defend given the difference in turnover. Some meters weight by volatility, some by a proxy for volume, most by nothing at all.
If a meter does not tell you its lookback period, you cannot interpret its output. The first question to ask of any strength dashboard is what window it measures, and the second is whether you can change it.
The circularity problem
A single currency does not have a price. Strength is always relative, so a meter derives eight numbers from 28 relationships that are themselves interdependent. If the dollar sells off hard, every other currency rises in the ranking, and the chart will show seven currencies strengthening when only one thing actually happened.
This is the most common misreading. A trader sees AUD near the top and NZD near the bottom, concludes the two have diverged, and takes AUDNZD. Often that is right. But if the top of the chart is crowded and the bottom holds only the dollar, the meter is describing a dollar move, and the correct expression of that view is a dollar pair, not a cross. The dollar index is a purpose built version of the same measurement and it is the cleaner instrument when the dollar is the story.
Where the tool earns its place
Pair selection. If you already have a directional view and want the pair that expresses it with the most room, a strength dashboard shortens the search. Bullish the euro is a view. Whether to take it against the dollar, the yen or the Australian dollar is a question the meter can help answer in about ten seconds instead of flicking through 28 charts.
Exposure checking. If you hold three positions and all three are short yen, the meter makes that obvious. This overlaps with what a correlation matrix tells you, and the two together are more useful than either alone: the matrix shows how the pairs move together historically, the meter shows what the common currency is doing right now.
Context on a range day. When every bar sits near the middle of the scale, no currency is doing anything in particular, which is a reasonable prompt to stop looking for a trend continuation trade.
Where it fails
Strength meters lag by construction. Every one of them is an average of past returns, so the bars turn after the move, not before it. A meter that appears to lead price is almost certainly repainting, recalculating history as new data arrives so the chart looks prescient in the archive and behaves quite differently live. Our note on indicator repainting covers how to test for this: run the tool forward on a demo for a fortnight and compare it against the screenshots you took at the time.
They also flatten the reason for a move. A currency can be strong because a central bank surprised the market, because a risk event drove a safe haven bid, or because a large corporate flow crossed the tape. Those three have very different persistence and the bar chart looks the same for all of them. Pairing the meter with the economic calendar for the session is the minimum sanity check.
Choosing one
Prefer a meter where the lookback is visible and adjustable, ideally with two windows shown at once so you can see whether the short term reading agrees with the daily one. Prefer one that names its pair universe: eight majors is standard, and adding exotics without volume weighting makes the output noisier rather than richer.
Then test it against the thing you actually do. Take a fortnight of your own trades, mark the meter reading at entry, and see whether the trades taken with the meter's alignment did better than the ones against it. That is a small sample and will not prove anything statistically, but it will show whether the tool is telling you something you did not already know from the chart. Most traders find the honest answer is that the meter is a convenience for pair selection and nothing more, which is a perfectly good reason to keep it on the second monitor and a bad reason to enter a trade.
"A strength meter answers a question about the last four hours. Traders read it as an answer about the next four. That gap is where the money goes."
— Alex Onta, Executive Director, SINGUARD
Key Takeaways
- Strength meters decompose 28 pairs into eight relative scores, and the lookback period drives most of the output.
- Two meters disagree because lookback, weighting and pair universe are author choices, not a standard.
- A crowded top of the chart with one currency at the bottom usually means a single currency move, best traded directly rather than as a cross.
- Use it for pair selection and exposure checking, and test any meter that appears to lead price for repainting.
Frequently Asked Questions
How is currency strength calculated?
The meter measures the percentage change of each currency against the other majors over a chosen lookback, flips the sign where the currency is the quote side of the pair, averages the results and normalises them onto a common scale. With eight majors that means 28 pairs feeding eight scores.
Why do two currency strength meters show different results?
Because there is no standard. Each one picks its own lookback period, its own pair list and its own weighting scheme. A one hour meter and a daily meter can rank the same eight currencies in almost opposite order and both be calculating correctly.
Can a currency strength meter predict the next move?
No. Every strength meter is an average of past price changes, so it describes what has already happened. A meter whose bars appear to turn before price is usually repainting its history. Treat it as a summary of recent behaviour and as a shortcut for choosing which pair expresses a view you formed elsewhere.
About the Author
Alex Onta is an Executive Director at SINGUARD. He built eTrader, the terminal, the mobile apps, eTrader Broker, Copytrading, Business and Community, along with the worldwide clustered-server infrastructure it all runs on, with his brother Roman Onta helping on the design, and he leads that division today. Together with Roman he builds the Prop Firm CRM, the Broker CRM, Scalegram and CopySignals, and the two of them carry worldwide compliance, payment processing and international business structuring side by side. He lives and works in Dubai for most of the year. Meet the executive duo leading Singuard's five divisions.