Definition
Open Interest Buildup at Strikes
Strike-level open interest buildup shows which option strikes are attracting the most positions, marking likely support and resistance.
On the NSE option chain, the strikes with the largest call open interest tend to act as resistance (call writers defending that level), and the strikes with the largest put OI tend to act as support (put writers defending below). Tracking where OI builds and shifts through the day reveals where big participants expect price to be capped or held.
Indian Nifty and Bank Nifty traders map these strike-level OI walls each morning to define an expected range for the week, especially near weekly expiry when option-writer positioning dominates price behaviour around those strikes.
Related terms
- Open InterestOpen interest is the total number of outstanding futures or options contracts that have not yet been closed.
- Option ChainAn option chain is the full table of all available call and put strikes for a contract, with their prices and data.
- Max PainMax pain is the strike price at which the largest number of option buyers would lose money on expiry.
- Support and ResistanceSupport is a price level where buying tends to halt a fall; resistance is a level where selling tends to cap a rise.
Plain-English explainer from The Dispatch Investors Encyclopedia. General information, not financial advice.