Index option chain & OI analysis

How StrikeWatch reads an index option chain

Calls are on the left and puts on the right of each strike, with the current index level marked between the two nearest strikes and in-the-money options shaded. Pick an expiry and how many strikes around the at-the-money strike to show.

Open interest (OI) and change in OI

OI is the number of open contracts at a strike. Change in OI compares it with the previous trading day (for NIFTY you can also compare with 5, 15 or 60 minutes ago), for the strikes near the money.

Buying, writing, short covering and unwinding

Each option is labelled from its price and OI change: buying (price up, OI up), writing (price down, OI up), short covering (price up, OI down) or unwinding (price down, OI down). Changes too small to read are marked quiet, and weak moves are faded. These labels are inferences from price and OI, not records of individual trades.

Put-call ratio (PCR)

Total put OI divided by total call OI across every strike of the selected expiry.

Max pain

The strike at which option buyers across the whole chain would receive the least at expiry, based on current OI.

OI support and resistance

The strikes with the highest put OI (support) and the highest call OI (resistance) within 15 strikes of the at-the-money strike.

Strong support and resistance

Strikes where a large put OI wall (support, below the index) or call OI wall (resistance, above it) lines up with fresh writing and with the index's 15-minute, hourly and daily moving averages (EMA, DEMA, SMA). The more of these meet at one strike, the stronger the level; each level lists its reasons.

Index future: VWAP, premium and OI

The strip under the index level shows its nearest-month future. VWAP is the future's volume-weighted average price for the day: above it, buyers have paid up through the day; below it, sellers. The premium is the future minus the index, also as a yearly percentage, which normally sits near interest rates minus dividends (about 4–6%). The future's open interest against the previous day, with its price change, gives long build-up, short build-up, short covering or long unwinding.

Index sentiment

Combines the call and put activity within three strikes of the money, weighting each change by the money behind it. It describes recent positioning; it is not a forecast.

Prices and OI come from a broker market-data feed. During market hours the page and its prices refresh about every 15 seconds (weekdays, 09:00–16:00 IST); outside them it shows the last session's data. Data can be delayed or wrong. StrikeWatch is free to use, is not affiliated with NSE or BSE, and does not give investment advice.