WST·West Pharmaceutical Services, Inc.

Realized volatility (21d)

23.0% 44th pct

Below its peak

-21.1%

vs 200-day average

+21.8%

Up days (1y)

53%

West Pharmaceutical Services, Inc. is currently running 23.0% annualised volatility over the last 21 sessions. Measured against WST's own 13 years of daily returns rather than a market-wide average, that is the 44th percentile — close to its own typical level, against a typical reading of 24.4%. 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.

WST is trading -21.1% below its running peak. Across 12 full years on file, its median worst-drawdown-in-a-year was -22.9%, and the deepest was -53.0% in 2022. The current pullback is therefore shallower than what this stock gives back in a typical year, which is context worth having before treating it as a dislocation.

Price sits +21.8% from its 200-day moving average. Against every other day in its history, that gap ranks at the 85th percentile — a wider gap than this stock usually carries. Over the past year WST closed higher on 53% of sessions, and it is currently 3 sessions into a rising streak.

On October specifically: over 13 years of records, WST finished the month higher 9 of 13 times, with a median return of +2.7% and an average of +1.3%. Its strongest month historically has been June at +4.6% on average, its weakest February at -2.1%. 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: WST has opened more than 2% away from the prior close in 91 of 3,267 sessions (2.8% of the time), with the largest gaps running +9.1% and -15.7%. 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 WST's own 13-year history, not a peer group or index.