Exposure attribution
Attribution is the difference between knowing a number moved and being able to say why. In currency terms, it means splitting a reported effect into rate, volume, mix and timing — and being able to walk any piece of it back to the contract it came from.
What it decomposes into
A currency movement in reported results is rarely one thing. Part is the rate itself. Part is volume — more or less business done in the exposed currency. Part is mix, as the shape of the business shifts between entities and currencies. Part is timing, where exposures netted on paper but not in the same period. Attribution separates these, and the proportions are usually a surprise.
Why the total cannot answer the question
A board asks how much of the movement was the market and how much was the business. A single consolidated figure cannot distinguish them, because both are already inside it. The same is true for every follow-up: which entities moved it, how much was committed versus forecast, what netted on paper but not in time. These are not harder versions of the same question — they are questions a total is structurally incapable of answering.
Why it is difficult in practice
The inputs live in different systems on different bases. Exposures sit in the ERP, hedges in the treasury management system, intercompany positions in subledgers, and the plan in a spreadsheet. Entities close on different calendars. The same contract appears under different identifiers. Reconciling all of it to one basis, so that the parts genuinely sum to the reported total, is most of the work — and it is why attribution is usually reconstructed by hand, after the quarter, when it is too late to act on.
What good attribution requires
Every figure has to carry its source, so any number in the summary can be opened to the contract underneath it. Estimates have to be labelled as estimates. A missing value has to read as missing rather than as zero. Without those properties the decomposition may be arithmetically correct and still not survive its first serious question.
See this on your own numbers.
The attribution map is free and built from public filings — the drivers that move the number in your industry, and where peers took the hit. No data required, nothing to sign.