Reading an option chain for intraday trading means watching four numbers together on one live screen — price, Open Interest (OI), Change in OI, and Implied Volatility (IV) — and using how they move against each other to decide a strike, not staring at any single column in isolation. Most traders open the chain, see a big OI number on some strike, and treat it as a signal by itself. That's the habit this page is here to fix.
You'll find the option chain on Zerodha Kite, Sensibull, the NSE website, or any broker's F&O screen — same data, slightly different layout. What matters is knowing which columns actually move the needle for an intraday decision and which ones are mostly noise.
Key takeaway
Reading an option chain for intraday trading means watching price, Open Interest, Change in OI, and IV together — not any single column alone. A rising OI number by itself is often noise; combined with price direction it tells you whether traders are adding fresh positions or exiting old ones, which is what actually helps you pick a strike and side before the move plays out.
What Is an Option Chain (And Why Intraday Traders Watch It)
An option chain is the live table listing every strike price for an index or stock's options, with call data on the left, put data on the right, and each row showing OI, Change in OI, Volume, Last Traded Price, and IV side by side.
For an end-of-day investor, the chain is something you check once before placing an order. For an intraday trader, it's a screen you keep open the whole session, because the numbers update tick by tick, not just once at day's close the way an OI Spurts report does. A strike that had modest OI at 9:20 AM can look completely different by 10:30 AM, and that shift is the actual signal.
Two traders can look at the exact same chain and walk away with different reads. One is checking which strikes have real participation building right now. The other is just eyeballing which number is biggest. This page is about becoming the first kind.
How to Read the Option Chain Columns for Intraday Trades
Six columns matter for an intraday read. Here's what each one is actually telling you in the moment, not just what it's called:
| Column | What it tells you intraday |
|---|---|
| LTP (Last Traded Price) | The current premium — moves with the underlying and with Implied Volatility, not price alone |
| OI | Total contracts still open on that strike — a headcount of live positions, not activity |
| Chng in OI | How much OI moved since the previous session's close — this is what actually flags fresh buildup or unwinding happening today |
| Volume | Contracts traded today, cumulative — tells you how "alive" a strike is right now |
| IV | Implied Volatility — the market's forecast of how much the underlying will swing, baked into the premium |
| Bid-Ask Spread | How tight the quotes are — wide spreads mean poor liquidity, which matters a lot more intraday than for a positional trade |
The one mix-up that trips up almost every new trader here: OI and Volume are not the same thing, and rising volume does not mean rising OI. OI counts positions that are still open; Volume counts trades executed today, regardless of whether they opened or closed a position. A strike can show heavy Volume with OI barely moving. That's traders opening and closing positions on the same strike all day, not fresh conviction building. Our full OI explainer walks through this distinction with worked examples if you want the deeper version; here, the short version is enough to read the chain correctly.
IV matters differently. It tells you whether the premium you're about to pay is expensive relative to how much the underlying is actually expected to move, not just what the ₹ number looks like. See our explainer on what IV means in the option chain if a premium looks unusually high or low and you can't tell why.
Reading OI Buildup Patterns During the Day
Change in OI only tells you half the story on its own. Pair it with price direction on the same strike and you get one of four patterns traders watch for:
Long Buildup
Fresh long positions are being added as price rises — traders are buying and holding, bullish while it continues
Short Buildup
Fresh short positions are being added as price falls — traders are selling and holding, bearish while it continues
Short Covering
Price is rising while OI falls — shorts are closing out, often a sharp bounce rather than a fresh bullish trend
Long Unwinding
Price is falling while OI falls — existing longs are exiting, not fresh bears attacking
The distinction that actually matters intraday: Long Buildup and Short Covering can look identical on a price chart. Both push price up. But they mean opposite things about who's driving the move. Buildup means new conviction is entering. Covering means old positions are being closed. Confusing the two is how traders chase a bounce that was really just shorts running for the exit.
None of these four patterns predict what happens next by themselves. They describe what already happened between the last print and now. Use them to understand who's active on a strike, not as a standalone entry signal. If you want to see this at a market-wide level rather than strike-by-strike, NSE's own OI Spurts report flags stocks with unusual OI activity across the exchange.
How to Pick a Strike Price for Intraday Using the Option Chain
Start from liquidity, not from which strike has the cheapest premium. A strike with thin OI and a wide bid-ask spread can eat more of your profit in slippage than a bad directional call would.
Say Priya, a software employee in Bengaluru who recently got F&O access after two years of index SIPs, is watching Nifty trade around ₹24,000 intraday and has just seen a Long Buildup pattern on the 24,000 Call. Nifty's lot size is 75 at the time of writing — always confirm the live figure on your broker's app before trading, since NSE revises it periodically.
- Check OI concentration first. The 24,000 CE (at-the-money) shows OI of 45 lakh contracts with a ₹0.50 bid-ask spread. A strike two notches out, the 24,200 CE, shows only 12 lakh OI and a ₹1.50 spread. The ATM strike is the more liquid trade: easier to enter and exit fast, which matters more intraday than the extra leverage further out.
- Compare premium against IV, not just against ₹ cost. The 24,000 CE is priced at ₹120 (₹9,000 for one lot at the current lot size), the 24,200 CE at ₹45 (₹3,375 a lot). The OTM strike looks cheaper, but check its IV against the ATM strike's. A disproportionately high IV on the cheaper strike often means the market is already pricing in a bigger move than you're betting on, not that you've found a discount. Our premium calculation explainer breaks down exactly how IV feeds into that ₹120 vs ₹45 gap.
- Match the strike to how far you actually expect price to move today. An ATM strike moves close to point-for-point with the underlying and costs more upfront. A far OTM strike is cheaper but decays fast and needs a bigger move just to turn profitable before the session ends. Not a trade to reach for by default just because the premium looks small.
Common Misunderstandings
A big Change in OI on a strike always signals a big move coming.
It signals fresh positions building, not direction — check price action on the same strike before assuming where it's headed.
OI and Volume are basically the same number.
OI counts positions still open; Volume counts contracts traded today. A strike can show heavy Volume while OI barely moves.
The option chain only matters close to expiry.
Intraday OI and price shifts show up in the chain in real time, well before expiry week arrives.