AON·Aon plc

Realized volatility (21d)

21.7% 67th pct

Below its peak

-32.9%

vs 200-day average

-16.6%

Up days (1y)

47%

Aon plc is currently running 21.7% annualised volatility over the last 21 sessions. Measured against AON's own 13 years of daily returns rather than a market-wide average, that is the 67th percentile — a little above its own norm, against a typical reading of 18.3%. The distinction matters because a number that looks calm for one stock is turbulent for another, and the absolute figure on its own tells you neither.

AON is trading -32.9% below its running peak. Across 12 full years on file, its median worst-drawdown-in-a-year was -15.6%, and the deepest was -38.9% in 2020. The current drawdown is already deeper than this stock's typical annual low point, which puts it in the part of its range where past recoveries began — and where past declines also continued.

Price sits -16.6% from its 200-day moving average. Against every other day in its history, that gap ranks at the 1st percentile — a narrower gap than it typically runs. Over the past year AON closed higher on 47% of sessions, and it is currently 1 session into a falling streak.

On October specifically: over 13 years of records, AON finished the month higher 7 of 13 times, with a median return of +0.9% and an average of +0.9%. Its strongest month historically has been November at +4.4% on average, its weakest December at -2.2%. Seasonality is a weak signal on its own — a decade is a small sample and regimes change — but it is a real distribution rather than a rule of thumb.

Overnight risk is measurable too: AON has opened more than 2% away from the prior close in 64 of 3,267 sessions (2.0% of the time), with the largest gaps running +10.5% and -11.6%. For anyone holding through an event, that rate is a better guide to overnight exposure than the intraday range.

All figures computed from 3,268 daily closes between 2013-10-15 and 2026-10-13, split-adjusted, recomputed daily. Percentiles are against AON's own 13-year history, not a peer group or index.