Put-Call Ratio (Open Interest) (120-Day)

Put-Call Ratio (Open Interest): The ratio of outstanding put contracts to outstanding call contracts at the close of the trading day, for options with the relevant expiration date.

Biogen Inc. (BIIB) had 120-Day Put-Call Ratio (Open Interest) of 1.0590 for 2026-09-15.

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Figures for 2026-09-15

Volatility Metrics
Historical Volatility (Close-to-Close)	0.3649
Historical Volatility (Parkinson)	0.3173
Implied Volatility (Calls)	0.3853
Implied Volatility (Puts)	0.3775
Implied Volatility (Mean)	0.3814
Put-Call Implied Volatility Ratio	0.9796
Implied Volatility Skew	0.0255
Option Statistics
Put-Call Ratio (Volume)	0.1964
Put-Call Ratio (Open Interest)	1.0590