The reason a figure quoted per year is earned for a week

A pool posted a strong figure and labelled it annual. The return had actually been earned during one exceptional week — a burst of trading fees from a volatile event — and then annualised by multiplying it out across fifty-two weeks. The other fifty-one weeks looked nothing like it. The annual label took a week that would not recur and projected it over a year, converting a lucky burst into an apparent steady rate no depositor would ever actually receive.

What everyone sees

A depositor reads the annual figure and hears a rate available for the coming year: this is what the pool pays, annually. The per-year unit implies the figure was measured or expected across a year. The depositor never suspects that a single unusual week was the entire basis, extrapolated fifty-two-fold, and treats a one-off as a recurring feature.

What is actually happening

Annualising a short measurement period assumes the period is representative, and a single strong week rarely is. Statistics on return reporting warn that extrapolating brief, favourable windows produces figures wildly detached from realised averages, especially when the window was chosen because it was good. The pool’s annual number is arithmetic performed on an outlier, and the outlier was selected precisely because it made the projection large.

Why it stays hidden

The hidden mechanism is representativeness abuse through the annual unit. By quoting per year, the pool implies a yearlong basis while using a week, and the reader assumes the sample is typical. The choice of a favourable week and its multiplication across a calendar are both invisible; only the impressive product is shown. A burst is dressed as a baseline.