The put/call ratio, explained
The short answerThe put/call ratio divides put activity by call activity: either volume (contracts traded that day) or open interest (contracts still open). Above 1 means more puts than calls. Extremes are often read as contrarian sentiment, but funds like SPY carry many hedging puts, so a ticker is best compared with its own history.
Two ratios, two questions
- Volume ratio = puts traded ÷ calls traded today. It is fast and noisy: it shows what traders did today.
- Open-interest ratio = open puts ÷ open calls. It is slow: it shows the positions that have built up, including long-dated hedges.
Why SPY’s ratio is usually high
Big investors buy SPY and index puts to protect their portfolios, and keep them for months. That makes SPY’s open-interest ratio sit well above 1 most of the time, while single stocks are usually below 1 (more calls than puts). A ratio of 1.5 can be ordinary for SPY and extreme for a stock.
The contrarian reading
When everyone is buying puts, fear is high — and fear tends to be highest near lows; when calls dominate, greed may be peaking. That is why extremes are read against the crowd. It works best with a long history and a measure of “extreme” for that ticker alone: on this site the Scanner marks a ratio that is unusual against the ticker’s own past (a z-score), not against a fixed number.
Limits
A put can be a bet on a fall or protection for shares; a call can be a bet on a rise or a covered call sold against shares. The ratio counts contracts, not intentions, so read it with open interest and volume and the rest of the picture.
Live example: SPY and QQQ today
From the close of Fri, Nov 13, 2026 — this box is rebuilt after every trading day.
SPY, Nov 13, 2026: open-interest ratio 1.85 (11,209,829 puts against 6,061,214 calls), volume ratio 1.20; against its own history the open-interest ratio is ordinary (z-score -1.7).
QQQ, Nov 13, 2026: open-interest ratio 1.11 (7,213,245 puts against 6,484,536 calls), volume ratio 1.04; against its own history the open-interest ratio is unusual (z-score -3.8).
The daily put/call history for any ticker is in its CSV download.
Questions and answers
What is a normal put/call ratio?
It depends on the ticker. Index funds like SPY usually have more puts than calls (a ratio above 1); most single stocks have fewer. Compare a ticker with its own history.
Is a high put/call ratio bearish?
It shows that many puts are held or traded. Many traders read very high readings as fear, which is often contrarian — but puts are also bought as routine protection.
Volume or open interest — which ratio is better?
They answer different questions: volume shows today’s trading, open interest the positions that have built up. Watching both avoids reading one day’s noise as a trend.
All 10 lessons: Learn · every term in one long page: the full guide · the numbers for any ticker: ETFs, stocks. For education only — not investment advice.