How to read the Nifty option chain

The option chain lists every Nifty strike for one expiry, with calls on the left and puts on the right. For each strike you see the premium (LTP), volume, open interest (OI) and the change in OI since the previous session. The strike closest to the current Nifty level is the at-the-money (ATM) strike.

OI is the number of contracts still open. Large call OI at a strike usually means option writers expect Nifty to stay below it; large put OI means writers expect Nifty to stay above it. The change in OI matters more than the total: it shows where fresh positions are being added today.

The put strike with the highest OI is often read as support, and the call strike with the highest OI as resistance. When those levels shift during the day — for example, put OI moving up to a higher strike — the range is shifting with it.

PCR = total put OI ÷ total call OI. Readings above 1 mean more puts are open than calls, commonly read as writers being comfortable below the market. Readings well below 1 suggest the opposite. Extreme readings in either direction can signal a crowded trade.

• Long buildup: price up, OI up — new buyers entering.
• Short buildup: price down, OI up — new sellers entering.
• Short covering: price up, OI down — sellers exiting.
• Long unwinding: price down, OI down — buyers exiting.

A single snapshot hides the story. The Option Clock plots call and put OI change in 5-minute steps, so you can see which side is adding positions and when. In the sample below, put writers keep adding through the morning while call additions lag — a pattern many traders read as a supportive session.

This guide is educational market analytics, not investment advice or a recommendation to buy or sell. Options trading carries substantial risk. Read our risk disclosure.