COI PCR Live — Intraday Change in OI Put-Call Ratio for Nifty, BankNifty & F&O Stocks
About COI PCR (Change in OI Put-Call Ratio)
COI PCR divides today's change in put open interest by today's change in call open interest: COI PCR = PE COI / CE COI. Unlike the regular put-call ratio, which is built from total accumulated OI, COI PCR looks only at positions opened or closed in the current session. That makes it far more responsive: fresh put or call writing shows up within minutes, while total PCR needs hours to drift. We compute it live every minute during market hours (9:15 to 3:30 IST) across the strike window you choose — auto ATM ± range, a fixed strike ± range, or hand-picked strikes.
COI Strength % and the dominance bands
A raw change-based ratio misbehaves early in the day, when the call-side change is near zero and the ratio explodes, or when OI is unwinding and the sign flips. The strength view fixes this by normalizing the imbalance: COI Strength % = ((PE COI − CE COI) / (|PE COI| + |CE COI|)) × 100, bounded between −100% and +100%. Above +60% is Put Dominance — the put side is decisively stronger, which in Indian index options usually reads bullish because put writers are betting support holds. Below −60% is Call Dominance, the bearish mirror image. Between the bands is Neutral: balanced activity, no edge. The same formula applied to total OI gives OI Strength %, the slower-moving confirmation line.
How day traders use it
The practical value of COI PCR is timing. Sentiment shifts appear in the change-in-OI data before they move the total PCR, so a COI Strength flip from Put Dominance toward the Call side often front-runs an intraday trend change. Watch for divergences too: if price is falling but COI Strength is climbing toward Put Dominance, put writers are absorbing the decline — a classic bounce setup. The third chart shows the raw PE and CE change-in-OI lines, so you can verify which side is actually adding contracts rather than trusting the ratio alone.
COI PCR is a sentiment gauge, not a standalone system. Read it alongside the classic Put Call Ratio for the accumulated-OI picture, the PE-CE Difference table for strike-level detail, and the PCR Trend chart to see where today's reading sits against the past year.
How to use the StockMojo COI PCR tool
- Select an underlying and expiry — Choose Nifty, BankNifty, Sensex or an F&O stock, then pick the expiry you trade. The nearest weekly expiry carries most of the intraday activity.
- Set the strike window — Start with ATM ± 10 strikes. Use Strike ± Range to anchor a fixed level, or Custom Strikes to isolate specific strikes you are tracking.
- Read the COI PCR line — A rising COI PCR means fresh put writing is outpacing call writing today (supportive); a falling line means call writers are in control.
- Check the dominance bands — On the strength chart, above +60% is Put Dominance, below −60% is Call Dominance, and the middle zone is Neutral. Sharp flips across the zero line often precede intraday trend changes.
- Confirm with the Change-in-OI chart — The PE vs CE change-in-OI lines show which side is actually adding contracts. Confirm a dominance signal against these lines and price action before entering a trade.
Frequently Asked Questions
What is COI PCR (Change in OI PCR)?
COI PCR is the Put-Call Ratio calculated from today's change in open interest instead of total open interest. It divides the intraday change in put OI by the intraday change in call OI, so it reflects only the positions traders are building or unwinding today — not the stale positioning carried from previous sessions.
How is COI PCR different from the regular PCR?
Regular PCR uses total accumulated open interest, which includes positions built over days or weeks, so it moves slowly. COI PCR uses only today's OI change, so it reacts within minutes to fresh put or call writing. Day traders watch COI PCR to catch sentiment shifts before they show up in the total PCR.
What is COI Strength % and how is it calculated?
COI Strength % normalizes the put-call imbalance to a bounded scale: ((PE COI − CE COI) / (|PE COI| + |CE COI|)) × 100. The result always sits between −100% and +100%, which avoids the division problems a raw ratio has when OI change is small or negative. OI Strength % applies the same formula to total open interest.
What do Put Dominance, Neutral and Call Dominance mean?
StockMojo classifies the strength reading into three bands: above +60% is Put Dominance (the put side is much stronger), between −60% and +60% is Neutral (balanced activity), and below −60% is Call Dominance (the call side is much stronger). The badges above the chart show the live classification for both COI and total OI.
Is Put Dominance bullish or bearish?
In Indian index options, heavy fresh put writing is usually read as bullish — sellers are collecting premium on the bet that support holds. So Put Dominance (strength above +60%) typically supports upside, while Call Dominance (below −60%) signals call writers defending levels overhead, which is bearish. Always confirm with price action before trading the signal.
Why can COI PCR spike or look extreme early in the session?
In the first minutes of trade the change in call OI can be near zero, so the ratio's denominator is tiny and the reading swings violently. This is inherent to any change-based ratio. The COI Strength % chart solves it — being bounded between −100% and +100%, it stays readable from the opening bell.
Which strikes are included in the calculation?
You control it. ATM ± Range follows the ATM strike automatically and sums OI across the chosen number of strikes on each side; Strike ± Range anchors the window on a fixed strike; Custom Strikes lets you hand-pick the strikes. A tighter range (ATM ± 5 to ± 10) keeps the reading focused on where the real intraday battle happens.
Can I see COI PCR for past trading days?
Yes. Switch to Historical mode and pick any past session — the tool rebuilds the full intraday COI PCR, strength bands and change-in-OI lines for that day, with the same expiry and strike-range controls as the live view. Historical access requires a paid plan.