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

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.

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

Price ↓
OI ↑
Volume ↑

Example

Meaning

✔ New sellers entering.
✔ Strong downside momentum.

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.

5. Long Unwinding

Price ↓
OI ↓

Meaning

Existing buyers are exiting.

No aggressive new shorts.

Often seen near the end of a rally.

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.

Bearish Option Chain

Look for

Heavy Call Writing

Resistance becomes strong.

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.

Intraday OI Signals

Bullish

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

Perfect bullish setup.

Bearish

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

Strong bearish momentum.

Strike Price Analysis

Suppose Nifty is at 25,000.

Interpretation

Resistance = 25,100

Support = 24,900

PCR (Put Call Ratio)

PCR = Put OI ÷ Call OI

Highest Probability Bullish Setup

✔ Price above 20 EMA

✔ Price above VWAP

✔ Fresh Long Build-up

✔ Put Writing

✔ Volume breakout

✔ OI increasing

Probability: High

Highest Probability Bearish Setup

✔ Price below VWAP

✔ Fresh Short Build-up

✔ Heavy Call Writing

✔ Lower High

✔ Volume increasing

✔ OI increasing

Probability: High

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)

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