OIData Blog

Guides and explainers on Open Interest, option chains, gamma exposure (GEX), volatility, FII/DII activity, and Indian index & stock F&O analysis — written for traders learning to read the data.

The Hedge Ladder: How Much Dealers Must Trade at Each Price Step, and Why a Jump Matters

By OIData Editorial Team ·

Dealer gamma is usually shown as a chart of bars by strike. The hedge ladder turns it into the number a desk actually watches: the futures that must be bought or sold if the index moves half a percent, one percent, two percent, in either direction. How it is computed strike by strike, how to read the sign, what a jump in the ladder means, and how it links to the corridor and the regime.

Hedge LadderDealer PositioningGEXGamma RegimeNIFTY
Read more →

Pin Conviction: How to Read Whether an Expiry Will Pin, and How Much to Trust It

By OIData Editorial Team ·

Every options trader has watched an index get walked into a strike on expiry afternoon. Pin conviction turns that hunch into a number: which strike is pulling price, how hard, how long it has held the lead, and whether the read is forming, weak, stable or locked. What goes into the score, how the states are meant to be used, and where the read fails.

Pin ConvictionDealer PositioningExpiry DayGEXNIFTY
Read more →

The Open Auction Session, Explained: How the NSE and BSE Pre-Open Works From 7 September 2026

By OIData Editorial Team ·

From 7 September 2026 the 09:00–09:15 pre-open on NSE and BSE becomes an Open Auction Session that mirrors the closing auction: market orders only in the first five minutes, a random close between 09:08 and 09:10, matching at 09:10. What changes, why it matters now that the close is an auction print too, and how to track the open.

Open Auction SessionOASPre-OpenNIFTYMarket Structure
Read more →

Expired Option Contracts: How to Read a Finished Strike From Listing to Its Last Session

By OIData Editorial Team ·

The day after expiry, an option contract disappears from most terminals, and with it the most complete lesson the market offers: a strike whose story has an ending. Why expired option contracts vanish, what a finished strike can teach about walls, decay and pinning, and where to read one day by day.

Expired ContractsStrike HistoryOpen InterestExpiryOptions Data
Read more →

Strike History: How to Read One Option Strike Day by Day, From Listing to Expiry

By OIData Editorial Team ·

The option chain is a photograph of every strike at one moment. Strike history is the film of one strike: its call and put, session by session, from the day the contract was listed to the day it expires. What the columns mean, how the four build-up labels read over consecutive days, and how to tell a wall that was built from one that just appeared.

Strike HistoryOpen InterestOption ChainOI InterpretationNIFTY
Read more →

Trading Expiry Day with Open Interest

By OIData Editorial Team ·

Expiry day has its own physics — brutal time decay, OI walls that act as magnets, and gamma risk. Here's how to read open interest on expiry and the traps to avoid.

ExpiryOpen InterestThetaOptions Strategy
Read more →

Finding Support & Resistance from Open Interest

By OIData Editorial Team ·

Heavy option open interest marks the levels the market is defending. Learn how to turn the OI on a chain into practical support and resistance — and how to spot a break.

Open InterestSupport ResistanceOption ChainLevels
Read more →

How to Read the NIFTY & BANK NIFTY Option Chain

By OIData Editorial Team ·

The option chain looks intimidating but follows a simple layout. Learn the columns that matter, how to spot support and resistance from OI, and a quick daily routine.

Option ChainOpen InterestNIFTYBANKNIFTY
Read more →