CLH·Clean Harbors Inc.

Realized volatility (21d)

15.8% 12th pct

Below its peak

-2.8%

vs 200-day average

+8.4%

Up days (1y)

57%

Clean Harbors Inc. is currently running 15.8% annualised volatility over the last 21 sessions. Measured against CLH's own 13 years of daily returns rather than a market-wide average, that is the 12th percentile — unusually subdued by its own history, against a typical reading of 25.2%. 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.

CLH is trading -2.8% below its running peak. Across 12 full years on file, its median worst-drawdown-in-a-year was -23.9%, and the deepest was -64.5% in 2020. 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 +8.4% from its 200-day moving average. Against every other day in its history, that gap ranks at the 54th percentile — close to the gap it normally carries. Over the past year CLH closed higher on 57% of sessions, and it is currently 1 session into a falling streak.

On October specifically: over 13 years of records, CLH finished the month higher 5 of 13 times, with a median return of -4.0% and an average of -1.0%. Its strongest month historically has been November at +3.4% on average, its weakest September at -1.7%. 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: CLH has opened more than 2% away from the prior close in 138 of 3,266 sessions (4.2% of the time), with the largest gaps running +24.7% and -10.0%. For anyone holding through an event, that rate is a better guide to overnight exposure than the intraday range.

All figures computed from 3,267 daily closes between 2013-10-14 and 2026-10-09, split-adjusted, recomputed daily. Percentiles are against CLH's own 13-year history, not a peer group or index.