Radar Perene / Archive / concept

What is a statistical anomaly?

◦ Written under index methodology v1 (in effect until 15 Jul 2026). The current series is v2 — readings quoted here may differ from those shown today. See the methodology.

Concept

In the Radar, a statistical anomaly is a move so far out of the ordinary that the engine singles it out as unlikely to be mere noise — a reading far from the historical mean of the series itself. In practice, it is the engine saying: "this almost never happens."

How to read it. A variable in anomaly is not, in itself, good or bad — it is a warning of rarity. The exchange rate, real rates, a monetary aggregate: when any of them breaks its own historical edges, the episode deserves attention, because moves like that tend to accompany regime inflections.

Why it matters. Intuition says the rare tends to unwind — that the excess returns to the mean. Sometimes it does. But the archive shows that it does not always: there are anomalies that correct in weeks and there are those that settle in as a new level.

What it is not. It is not a trade signal. "It is in anomaly" does not mean "it will soon revert." It means the present has left the common territory — and that what comes next must be observed, not presumed.

Related episodes: The dollar never came back (2020) · When the exchange rate dictates (2013 × 2024) · What the Perene Risk Index is →

Read also: The dollar never came back: when an extreme redefines the floor · What is the Perene Risk Index?

Characters: Statistical anomaly