Direct Answer
Put volume divided by call volume on index options, as published by Cboe in its index put/call ratio. Index options are heavily used by institutions for portfolio hedging. Because hedging demand keeps put volume high, the index ratio is usually above 1, and changes are read against its own history.
Index Put/Call Ratio: Formula, Meaning, Signals, Examples and How to Use It
How Is Index Put/Call Ratio Calculated?
Put volume divided by call volume on index options, as published by Cboe in its index put/call ratio. Index options are heavily used by institutions for portfolio hedging.
Formula: Index put/call = total index put volume / total index call volume
Inputs:
- Daily put volume on index options
- Daily call volume on index options
Worked example. If 900,000 index put contracts and 750,000 index call contracts trade in a day, the ratio is 1.20. The inputs are illustrative numbers, not market data.
Reading it. Because hedging demand keeps put volume high, the index ratio is usually above 1, and changes are read against its own history. A rise suggests more institutional hedging; a drop suggests less.
Limits. High put volume can mean hedging a long book, which is opposite to a bearish bet, so interpretation is ambiguous. It is a ratio of volume and not of open interest.
What is Index Put/Call Ratio?
Put volume divided by call volume on index options, as published by Cboe in its index put/call ratio. Index options are heavily used by institutions for portfolio hedging.
How to use Index Put/Call Ratio
Because hedging demand keeps put volume high, the index ratio is usually above 1, and changes are read against its own history. A rise suggests more institutional hedging; a drop suggests less. A reading alone is never a buy or sell signal; it needs context from price structure, volume, volatility and the broader market regime.
Strengths
- Because index options settle in cash and cover whole baskets, the ratio isolates activity tied to broad-market exposure.
- The daily tally is split by put and call at the exchange level, so the figure can be re-derived from published volume statistics.
- Reproducible when the formula and data convention are fixed.
Weaknesses and limitations
- Index options include many spread and multi-leg trades, in which each leg adds to put or call volume without being a standalone view.
- Index put volume is routinely higher than call volume, so the ratio is better judged against its own history than against 1.0.
- Correlated indicators can create false confidence by repeating the same underlying information.
Editorial and risk note
This page is educational content, not individualized investment advice. It should not imply guaranteed prediction, accuracy or outperformance.
Frequently Asked Questions
Is Index Put/Call Ratio a buy or sell signal?
No. Because hedging demand keeps put volume high, the index ratio is usually above 1, and changes are read against its own history. High put volume can mean hedging a long book, which is opposite to a bearish bet, so interpretation is ambiguous. A trade built on it still needs a trigger, an invalidation rule, a position size and realistic execution assumptions.
What is the best setting for Index Put/Call Ratio?
Index Put/Call Ratio is computed from daily put volume on index options; daily call volume on index options, so the choices that matter are the data convention and the window it is read over. Test those across instruments, regimes and out-of-sample periods instead of fitting one historical winner.
Can Index Put/Call Ratio be used by itself?
High put volume can mean hedging a long book, which is opposite to a bearish bet, so interpretation is ambiguous. It is a ratio of volume and not of open interest. For that reason it is read next to measures of direction, participation, valuation, liquidity and risk, not alone.
Does Index Put/Call Ratio work on every timeframe?
The calculation (Index put/call = total index put volume / total index call volume) can be run on any bar size, but behavior is not portable: a reading on a five-minute chart describes a very different market window from the same reading on a daily chart. Validate the exact timeframe before relying on it.
Why does Index Put/Call Ratio give false signals?
Index options include many spread and multi-leg trades, in which each leg adds to put or call volume without being a standalone view. Index put volume is routinely higher than call volume, so the ratio is better judged against its own history than against 1.0. Lag, noise and regime changes add to this, because market participants react to new information after the reading is calculated.
How should Index Put/Call Ratio be backtested?
Rebuild Index Put/Call Ratio from daily put volume on index options using point-in-time data, write the rules before testing, include delisted securities where relevant, model realistic fills and costs, reserve a validation sample and compare with a simpler baseline.