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.
Cisco Systems, Inc. (CSCO) had 20-Day Put-Call Ratio (Open Interest) of 0.3609 for 2026-05-21.
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