Historical Volatility (Parkinson) (30-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.

Spok Holdings, Inc. (SPOK) had 30-Day Historical Volatility (Parkinson) of 0.2037 for 2025-10-13.

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Figures for 2025-10-13

Volatility Metrics
Historical Volatility (Close-to-Close)	0.1944
Historical Volatility (Parkinson)	0.2037
Implied Volatility (Calls)	0.6517
Implied Volatility (Puts)	--
Implied Volatility (Mean)	--
Put-Call Implied Volatility Ratio	--
Implied Volatility Skew	--
Option Statistics
Put-Call Ratio (Volume)	--
Put-Call Ratio (Open Interest)	1.0250