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.

Prothena Corporation plc (PRTA) had 20-Day Put-Call Ratio (Open Interest) of 0.4127 for 2026-03-05.

For much more extensive volatility insights, check out our new product VolVue:

Over 300 data fields encompassing historical volatility, implied volatility, and put-call ratios for multiple time frames
Download data in CSV, Excel, JSON, or XML format
Up to 20 years of data history
52-Week Rank and Percentile for all metrics and time frames

10-Day 20-Day 30-Day 60-Day
90-Day 120-Day 150-Day 180-Day

Figures for 2026-03-05

Volatility Metrics
Historical Volatility (Close-to-Close)	0.5024
Historical Volatility (Parkinson)	0.6699
Implied Volatility (Calls)	0.8859
Implied Volatility (Puts)	0.5220
Implied Volatility (Mean)	0.7040
Put-Call Implied Volatility Ratio	0.5892
Implied Volatility Skew	--
Option Statistics
Put-Call Ratio (Volume)	0.0000
Put-Call Ratio (Open Interest)	0.4127