Historical Volatility (Parkinson) (20-Day)

Historical Volatility (Parkinson): The past volatility of the security over the selected time frame, calculated using the high and low prices on each trading day.

HealthStream, Inc. (HSTM) had 20-Day Historical Volatility (Parkinson) of 0.3015 for 2026-07-21.

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Figures for 2026-07-21

Volatility Metrics
Historical Volatility (Close-to-Close)	0.2488
Historical Volatility (Parkinson)	0.3015
Implied Volatility (Calls)	0.6384
Implied Volatility (Puts)	0.4677
Implied Volatility (Mean)	0.5530
Put-Call Implied Volatility Ratio	0.7326
Implied Volatility Skew	--
Option Statistics
Put-Call Ratio (Volume)	--
Put-Call Ratio (Open Interest)	--