Put-Call Ratio (Open Interest) (20-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.

iShares Biotechnology ETF (IBB) had 20-Day Put-Call Ratio (Open Interest) of 1.6068 for 2026-05-21.

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Figures for 2026-05-21

Volatility Metrics
Historical Volatility (Close-to-Close)	0.2401
Historical Volatility (Parkinson)	0.1927
Implied Volatility (Calls)	0.2256
Implied Volatility (Puts)	0.2286
Implied Volatility (Mean)	0.2271
Put-Call Implied Volatility Ratio	1.0129
Implied Volatility Skew	0.0824
Option Statistics
Put-Call Ratio (Volume)	0.1439
Put-Call Ratio (Open Interest)	1.6068