Open Interest (OI) is one of the best tools to identify whether a stock or index is bullish, bearish, or gaining momentum—but OI alone is not enough. Always combine it with price action and volume.

1. The 4 Basic Open Interest Rules

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2. Fresh Long Build-up (Best Bullish Signal)

Price ↑
OI ↑
Volume ↑

Example

Interpretation

✔ Buyers are entering.
✔ New positions created.
✔ Trend likely to continue.

Trade: Buy on pullbacks.

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3. Fresh Short Build-up (Best Bearish Signal)

Price ↓
OI ↑
Volume ↑

Example

Meaning

✔ New sellers entering.
✔ Strong downside momentum.

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4. Short Covering (Powerful Bullish Move)

Price ↑
OI ↓

Example

Price rises from ₹1200 to ₹1235

OI falls from 10 lakh to 8 lakh.

Meaning

Sellers are closing positions.

Price can rise quickly.

Usually happens after support holds.

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5. Long Unwinding

Price ↓
OI ↓

Meaning

Existing buyers are exiting.

No aggressive new shorts.

Often seen near the end of a rally.

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Option Chain Analysis

Bullish Option Chain

Look for

✅ High Put Writing

Example

Large Put OI means buyers believe the market will stay above those strikes.

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Bearish Option Chain

Look for

Heavy Call Writing

Resistance becomes strong.

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Change in Open Interest (Most Important)

Never rely only on Total OI.

Always watch

Change in OI

Example

Yesterday

OI = 10 lakh

Today

OI = 16 lakh

Increase = 60%

Fresh participation.

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Intraday OI Signals

Bullish

• Price above VWAP
• Price making Higher High
• OI increasing
• Volume increasing

Perfect bullish setup.

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Bearish

• Price below VWAP
• Lower Low
• OI increasing
• Volume increasing

Strong bearish momentum.

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Strike Price Analysis

Suppose Nifty is at 25,000.

Interpretation

Resistance = 25,100

Support = 24,900

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PCR (Put Call Ratio)

PCR = Put OI ÷ Call OI

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Highest Probability Bullish Setup

✔ Price above 20 EMA

✔ Price above VWAP

✔ Fresh Long Build-up

✔ Put Writing

✔ Volume breakout

✔ OI increasing

Probability: High

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Highest Probability Bearish Setup

✔ Price below VWAP

✔ Fresh Short Build-up

✔ Heavy Call Writing

✔ Lower High

✔ Volume increasing

✔ OI increasing

Probability: High

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Professional Traders Watch These 7 Data Points

1. Price Action
2. Open Interest Change
3. Volume
4. VWAP
5. Option Chain (Call & Put Writing)
6. PCR
7. Max Pain (for expiry trading)

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Practical Example (Bullish)

Imagine an F&O stock with:

• Price: ₹1,200 → ₹1,235 (+2.9%)
• Volume: +80% above average
• Futures OI: +12%
• Highest Put writing at ₹1,200
• Call OI at ₹1,250 starts reducing

This combination suggests fresh long build-up, with ₹1,200 acting as support and the possibility of continued upside toward ₹1,250 if momentum persists.

Practical Example (Bearish)

Imagine another stock where:

• Price: ₹850 → ₹825 (-2.9%)
• Volume: +90% above average
• Futures OI: +15%
• Heavy Call writing at ₹840
• Put OI reducing at ₹820

This indicates fresh short build-up, with sellers becoming more aggressive and downside momentum strengthening.

Best websites to track OI

• National Stock Exchange of India (NSE Option Chain & Futures OI)
• BSE
• Sensibull
• Opstra
• TradingView

For the highest accuracy, don’t make trading decisions based on OI alone. Wait for confirmation from price action, volume, and key support/resistance levels.

open intrest data sites

Website	Best For	Free
NSE India	Official Futures & Option OI data	✅
Sensibull	Option Chain, OI Analysis, PCR	✅ Limited
Chartink