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.
By OIData Editorial Team ·
Every option loses value as time passes, and the loss speeds up near expiry. What theta decay is, how 13 NIFTY expiries in 2026 actually decayed through the day, what weekends really cost in six 2026 examples, and why theta is not free money.
By OIData Editorial Team ·
A gamma blast is a cheap option multiplying in a few hours on expiry day. Why gamma makes it possible, a real NIFTY example from 15 September 2026 in which the 23,300 put rose 27 times from its low, the part dealers' hedging and the closing auction played, and why most cheap expiry-day options still finish at zero.
By OIData Editorial Team ·
When price rises while open interest falls, shorts are buying back: short covering. When both fall, longs are selling out: long unwinding. What each means, how a short-covering rally differs from fresh buying, whether long unwinding is bullish or bearish, and why expiry week fills the data with exits that are really rollovers.
By OIData Editorial Team ·
OIData's 21 tutorial videos, put in learning order as one course of about an hour: reading the chain and open interest first, then futures and stocks, the price of movement, dealer positioning, the trading day and the reference pages. What each lesson teaches and what to read alongside it.
By OIData Editorial Team ·
A routine for reading the NIFTY option chain during the session: what to check at the open, how to find the walls and the corridor, why the change in open interest matters more than the total, what the build-up stripes say, and when to look again. Each step points to the moment in the video tutorial that shows it.
By OIData Editorial Team ·
Delta, gamma, theta and vega in plain words: what each number on an option chain means, how to read them off a real NIFTY chain, how they change as expiry approaches, what they say about a whole position, and where the dealer-level versions of the same numbers come in.
By OIData Editorial Team ·
Before a budget, a policy decision or a set of results, options price in the unknown. Once it is known, that price drains out, and an option can lose value even when the index moves the right way. What IV crush is, how much it costs, two real examples from 2026, and where to see it building.
By OIData Editorial Team ·
How many index futures foreign institutions hold long against short, from the exchange's participant-wise report. How the ratio is worked out, what 8% long means, why it has sat low for most of 2026, why the change says more than the level, and what it cannot predict.
By OIData Editorial Team ·
Most open interest at a strike is a writer's promise. What put writing and call writing mean, why written strikes behave like floors and ceilings, how to tell fresh writing from buying in the open interest, what covering looks like, and what writing cannot tell you.
By OIData Editorial Team ·
NIFTY options expire on Tuesdays and SENSEX options on Thursdays. Where that rule comes from, which contracts are weekly and which are monthly, what time an expiring contract really settles, and the 2026 dates when a holiday moves the NIFTY expiry to a Monday.
By OIData Editorial Team ·
Open interest is published in units and quoted in lots, and the two are routinely mixed up. What a lot size is and who sets it, how to convert open interest between units and lots, why a lot-size revision breaks a chart, and how to keep the numbers on a chain, a broker terminal and an exchange report on the same footing.
By OIData Editorial Team ·
A live option chain shows where open interest is. A historical option chain shows how it got there, and that sequence is where most of the learning is. What a stored chain lets you study that the end-of-day figures cannot, how replay works across the chain, the OI chart, the dealer cockpit and the Session Chart, and a way to use it.
By OIData Editorial Team ·
A whole option chain can be turned into one picture: the probability the market assigns to every finishing level at expiry. What the implied distribution is, how it is read off option prices, why its left tail is fat, how it relates to the expected move and max pain, and what it can and cannot tell you.
By OIData Editorial Team ·
A break of the day's high is a price fact. Whether it was driven by fresh positioning or by drift is an open-interest fact, and the two together are what breakout confirmation means. How the option book, the futures build-up and volume confirm or undercut a break, and the tags that mark the exact interval it happened.
By OIData Editorial Team ·
SENSEX options give an index trader a second weekly expiry, a different strike ladder and a thinner book than NIFTY. What is the same in a SENSEX option chain, what is different, which reads carry across, and where the two chains can be read side by side.
By OIData Editorial Team ·
The at-the-money straddle is the market's price for movement, and charted through the session against spot it becomes a running verdict on whether movement is beating decay. How to read the straddle premium against the underlying, why the strike rolls, what the straddle open-interest line adds, and a day when a falling index made the straddle richer.
By OIData Editorial Team ·
A NIFTY future almost never trades exactly at the index. The gap is the basis, and the cost of carry is the reason it exists. What the two numbers measure, how the annualised figure is computed and why it misbehaves near expiry, what a fat premium and a discount have tended to mean, and the dividend-season trap.
By OIData Editorial Team ·
Every month the open interest in NIFTY futures has to move from the expiring contract to the next one. What the rollover percentage and the roll cost measure, why they matter most in expiry week, how to read a high or low roll, and the mistakes the headline number invites.
By OIData Editorial Team ·
India VIX is quoted every day and understood less often than it is quoted. What the number actually measures, how to turn it into an expected daily move, why it is compared with realised volatility, what its percentiles say, and the ways it gets misread.
By OIData Editorial Team ·
Open interest levels are usually read off a table at the end of the day. Drawn on the price chart minute by minute, they become something else: a record of how the call wall, the put wall, the pin and the gamma flip moved while the index traded. How to read intraday open interest on a candle chart, what each line means, and what the read line does and does not claim.
By OIData Editorial Team ·
The Shoonya API from Finvasia is free, streams open interest on its touchline feed, serves candles at nine intraday intervals with OI, and allows one WebSocket per session. What that buys an options-analytics pipeline and what is left to build.
By OIData Editorial Team ·
The Kotak Neo API charges no subscription and streams quotes across NSE, BSE, MCX and currency segments, but its own support page says historical data is not available. What that means for an options-analytics pipeline and what is left to build.
By OIData Editorial Team ·
The Alice Blue API is free and its WebSocket depth feed carries open interest, but its history endpoint serves 1-minute and daily candles only, and only outside market hours. What that means for an options-analytics pipeline and what is left to build.
By OIData Editorial Team ·
The Groww API is a paid subscription with a rich quote, an option-chain endpoint with Greeks, candles in fixed windows and a live feed. What that buys an options-analytics pipeline, the three-month intraday history limit, and the analytics still to build.
By OIData Editorial Team ·
What the Fyers API gives an options-analytics pipeline: free v3 access with quotes, depth, candle history in 100-day windows, a 200-symbol data socket and a strict rate budget, and the layers it leaves you to build.
By OIData Editorial Team ·
India VIX is one number. The IV term structure shows implied volatility by expiry, the 25-delta skew shows it by strike, the volatility risk premium compares it with what the index delivered, and the surface holds all of it. How to read each shape, with a worked NIFTY example.
By OIData Editorial Team ·
A seasonality chart overlays each year of NIFTY from 1 January so the shape of every year can be compared. How the lines are built, how to read the month tiles, where the patterns come from, and why a ten-year tendency is context for your analysis rather than a forecast.
By OIData Editorial Team ·
An open interest chart draws call and put OI as bars at every strike, so the walls stand out as tall bars. What the walls mean, why today's change overlay decides whether a wall is alive, what the cumulative pair adds, and how replaying the session with a time slider turns one picture into a story.
By OIData Editorial Team ·
Open interest is a total; the change in OI is the flow. How to read the change in call and put open interest interval by interval, what Diff in OI, direction of change, Day Strength and Flow mean, and why the sequence of intervals tells you more than the daily figure.
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.
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.
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.
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.
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.
By OIData Team ·
The Angel One API streams free ticks with OI across NSE, BSE and MCX and its login is fully scriptable. What that means for options analytics pipelines.
By OIData Team ·
What the Zerodha API's market-data surface actually provides for options analysis — ticks, depth, candles, OI — and the analytics it leaves you to build.
By OIData Team ·
The Upstox API serves free ticks, deep candles and open interest. What that data surface covers for options analysis, its limits, and the ready-made layer.
By OIData Team ·
The Dhan API pairs a month-long static token with 20-level depth — and prices data at ₹499 + GST. The analytics consumer's guide to what that buys.
By OIData Editorial Team ·
India's closing auction session went live on 3 August 2026 — and the first two NIFTY closes printed 200.95 and 151.45 points above the frozen tape, the second on a weekly expiry where the print settled the options. What CAS is, what the data shows, and how to track it.
By OIData Editorial Team ·
The market publishes its own forecast of how far it will travel, and it costs one addition to read: the at-the-money straddle. What it means and how to use it.
By OIData Editorial Team ·
Reading buildup on one stock is easy. Ranking 200 of them to find where positions are actually being built is where a screener earns its keep.
By OIData Editorial Team ·
Gamma exposure maps where option-hedging pressure sits on the chain — and whether that hedging will absorb today's moves or amplify them. Here's how to read it.
By OIData Editorial Team ·
A closed exchange is not a neutral day for an options position. Expiry shifts, theta keeps running, and some holidays close clearing but not trading.
By OIData Editorial Team ·
The gamma flip is the index level where net gamma exposure crosses zero — the boundary between a market that absorbs moves and one that amplifies them.
By OIData Editorial Team ·
India has no public trade tape, but per-strike volume still gives away where attention suddenly arrives. How volume bursts are measured, and how to read them.
By OIData Editorial Team ·
Nine conditions worth being told about rather than watching for, what each one actually fires on, and how to set thresholds that don't drown you in noise.
By OIData Editorial Team ·
Negative-gamma names move differently: hedging chases price instead of absorbing it. How to screen 200 F&O stocks for that condition and what to do with it.
By OIData Editorial Team ·
A 0-100 fear and greed gauge for Indian markets, built from seven sentiment inputs each normalised against its own history. What it measures, and what it cannot.
By OIData Editorial Team ·
Futures OI gives the cleanest read on directional positioning. Learn to combine it with price for buildup signals, read the basis, and interpret rollovers around expiry.
By OIData Editorial Team ·
PCR sums up option positioning in a single number, but it's widely misread. Learn the formula, why it's often contrarian, and why fixed thresholds are a trap.
By OIData Editorial Team ·
NIFTY and BANK NIFTY look similar but trade differently. Learn why BANK NIFTY is more volatile, how their OI walls behave, and how to adjust your reads for each.
By OIData Editorial Team ·
A plain-English glossary of the futures and options terms you'll meet on the option chain and in OI analysis — from ATM to vega, with links to deeper guides.
By OIData Editorial Team ·
Open interest is powerful but easy to misread. Here are the ten mistakes that trip up most traders — and how to avoid each one.
By OIData Editorial Team ·
GIFT Nifty trades when Indian markets are shut, giving an early read on how the NIFTY may open. Learn what it is, how to use the implied open, and why the gap can fade.
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.
By OIData Editorial Team ·
Straddles and strangles let you trade the size of a move instead of its direction. Learn how each is built, when to go long vs short, and the risks that catch people out.
By OIData Editorial Team ·
Implied volatility is the market's forecast of future movement, baked into option prices. Learn what drives it, how India VIX fits in, and why IV crush catches buyers out.
By OIData Editorial Team ·
NSE breaks F&O open interest into Client, Pro, FII and DII. Learn what each category is, why Pro and FII are watched as "smart money," and how to read the data without falling for myths.
By OIData Editorial Team ·
FIIs and DIIs move the Indian market. Learn what the daily buy/sell figures mean, why FII and DII flows often pull in opposite directions, and how to read them without overreacting.
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.
By OIData Editorial Team ·
Max pain is the strike where option buyers lose the most at expiry. Learn how it's calculated, why price often drifts toward it, and why it's a tendency — not a rule.
By OIData Editorial Team ·
Combine price direction with the change in open interest and you get four signals that describe what the market is actually doing. Here's how to read all four.
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.
By OIData Editorial Team ·
Volume measures activity; open interest measures commitment. Confusing the two leads to bad reads. Here's how they differ and how to use them together.
By OIData Editorial Team ·
Open interest is the number of derivative contracts still open in the market. Here's what it really measures, how it changes trade by trade, and why it matters.
