The put/call ratio compares the amount of put-option activity with call-option activity. Depending on the dataset, it may use trading volume or open interest, and it may cover a particular index, exchange, or group of securities.
How it works
A ratio above 1 means the chosen put measure exceeds the corresponding call measure; below 1 means calls exceed puts. But the interpretation changes with the market, time period, and whether volume or open interest is used.
A put can be bought for downside protection, sold to collect premium, or used in a multi-leg strategy. The aggregate ratio therefore cannot identify the directional intention behind every contract.
Why it matters
Put/call ratios can help describe whether options activity is unusually skewed relative to history, especially when used with other positioning and volatility data.
The ratio is not a simple 'high = bearish' or 'low = bullish' signal. A large number of puts can reflect hedging rather than a direct forecast of falling prices.
A simple market example
Put open interest rises above call open interest before a major event. Some investors may be hedging long stock portfolios, so the high ratio does not prove that the market will fall the next day.
Common mistakes
Mixing a volume-based ratio with an open-interest ratio as if they were the same dataset.
Assuming every put represents a bearish directional bet and every call a bullish one.
Frequently asked questions
What is the difference between put/call volume and open-interest ratios?
Volume measures contracts traded during a period; open interest measures contracts that remain open.
Is a high put/call ratio bullish or bearish?
It depends on context. It can reflect fear, hedging, option-selling strategies, or other positioning.
Should the ratio be compared with a fixed threshold?
It is usually more useful to compare the same series with its own history and understand the underlying market and methodology.
Educational content only. Definitions describe common market usage and may vary by jurisdiction, instrument, or institution.