Market Data

Everything Is Rising, Almost Nothing Is Rising Much: The Breadth Trap

A diffusion reading that says most inputs are rising looks like broad inflation and reads as alarming. Weight the same basket by magnitude and it can collapse onto a single contributor. Breadth and magnitude are different questions, and confusing them is a trap.

Here is a number that looks scary and is easy to misread: of the 16 manufacturing input series we track, 12 are on a rising trend. That is a high-breadth reading, the kind that gets summarized as "broad-based inflation" and sets off alarms. But breadth answers only one question, how many things are rising, and says nothing about the second, how much. Weight the same basket by magnitude and a very different picture appears: the single largest contributor alone accounts for roughly 33% of the total increase. Breadth says everything is up. Magnitude says almost nothing is up much, except one or two things that are up a lot.

Two questions, two answers

Breadth and magnitude are genuinely different measurements, and a diffusion index reports only the first. A basket where sixteen inputs each rose one percent has the same breadth as a basket where fifteen rose a hair and one rose forty percent, but the two demand completely different responses. The first is broad, mild inflation you hedge across the board; the second is a concentrated shock you hedge surgically while leaving the rest alone. Reading the breadth number and inferring the broad response, when the reality is the concentrated one, is the trap, and it leads directly to over-hedging the calm inputs and under-hedging the hot one.

Why breadth misleads exactly when it looks worst

The cruel part is the timing. Breadth readings look most alarming precisely when one input is spiking hard, because a big move in one series often drags correlated series up with it, lifting the count of "rising" inputs even though the magnitude is concentrated in the original mover. So the moment a diffusion index screams "everything is rising," it is often the moment the increase is least broad and most concentrated. The high-breadth headline and the concentrated reality tend to arrive together, which is exactly when a manager most needs to check the magnitude decomposition before reacting to the count.

Counting how many prices rose is not the same as measuring how much cost rose. The first makes a headline; the second makes a hedge.

Read both, respond to magnitude

The discipline is to look at breadth and magnitude side by side and let magnitude drive the response. If breadth is high but concentrated, as it is now with one contributor doing roughly 33% of the work, the correct move is surgical: hedge the concentrated exposure hard and treat the rest as the mild background it is. If breadth is high and magnitude is genuinely even, then broad hedging is warranted. The diffusion number is a useful first alarm, but it is the beginning of the analysis, not the end, and acting on it alone is how you end up fighting the wrong fire.

One line's magnitude, six years of it

Over the 36-year record copper producer prices have moved decisively rather than oscillated: from 127.60 at the close of 1990 to 557.23 today, up 337%, and now at the top of its 36-year range. A change of that size across a span this long is a level shift, not a cycle, and planning that assumes a return to the 1990 figure is planning against the whole record.

The cost pressure and diffusion signals track both how broad and how large the input-cost move is. See the full basket

Published 2026-08-06.