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Glossary

modal outcome

most probable outcome · mode of the distribution · base case

The modal outcome is the single most probable scenario in a probability distribution — the mode, not the mean. In macro forecasting it names the path the market or a policymaker treats as the base case, distinct from the probability-weighted average across all scenarios.

How it works

The mode is the peak of a probability distribution — the outcome assigned the highest single probability. It diverges from the mean (probability-weighted average) when the distribution is skewed: a forecaster can hold a pause as the modal outcome while the expected path embeds cut risk in the tails.

Why it matters now

In 2025-26 rate watchers distinguish the modal FOMC path — a hold — from forward-curve pricing, which is a probability-weighted blend. When the curve prices easing the desk often reads it as tail-weighted optionality, not a forecast that a cut is the single most likely next move.

Example

In late 2025, with the FOMC on hold, a hold at the next meeting was the modal outcome — the single most probable decision — even as SOFR futures embedded, say, 15bp of expected easing across that window. The 15bp reflects a skew: a high-probability hold blended with a lower-probability 25bp cut, so the probability-weighted mean drifted below the mode of zero change.

Mechanism

mode = argmax P(x); distinct from mean = Σ x·P(x). Equal only for symmetric distributions.

How desks use it

  • Separating the FOMC's base-case hold from probability-weighted cut pricing in SOFR futures
  • Reading whether curve-implied easing reflects a forecast or tail optionality

Frequently asked

What is a modal outcome?
A modal outcome is the single most probable scenario in a forecast distribution — the mode, the outcome assigned the highest individual probability. It is distinct from the mean or expected value, which is the probability-weighted average across every possible outcome. In rates analysis, the modal path might be a hold even when the average path embeds easing.
How does the modal outcome differ from the expected value?
The modal outcome is the most likely single scenario, while the expected value is the probability-weighted average of all scenarios. They coincide only when the distribution is symmetric. With skew — say a high-probability hold plus a smaller chance of a deep cut — the mean can sit well below the mode, so the curve prices easing the base case does not contain.
Why does the distinction between modal and mean outcome matter for reading rate markets?
The distinction matters because forward curves price the probability-weighted mean, not the mode, so curve-implied easing can overstate the most likely policy move. A desk that reads 15bp of curve-priced cuts as a forecast misreads tail-weighted optionality; the modal next move may still be a hold, with the mean dragged down by low-probability cut scenarios.
Is a pause the modal outcome the same as the market pricing no cuts?
No. A pause being the modal outcome means a hold is the single most probable decision, but the market can still price expected easing simultaneously. The forward curve blends all scenarios into one weighted average, so a high-probability hold and a smaller-probability cut combine into a curve that shows partial easing even when no cut is the most likely move.

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By The Ledger DeskLast reviewed 2026-06-20