Options questions, answered

Open interest is the total number of option contracts in a strike that are still open and not yet squared off or settled. It counts positions, not trades. Rising open interest means fresh contracts are being created and new money is entering that strike; falling open interest means existing positions are being closed out.

Look for the strikes carrying the largest put and call open interest around the current spot. The heaviest put strike below spot is commonly treated as a support reference and the heaviest call strike above spot as resistance. Then watch change in open interest through the session — a level being defended will keep adding open interest, while a level about to break usually sheds it.

Change in open interest shows what is happening today, while standing open interest shows what was already there. A strike can hold a very large position built up over weeks yet see no fresh activity, and another can be quiet in absolute terms but adding aggressively right now. Reading both together separates old positioning from live intent.

Volume counts every contract traded during the session and resets to zero the next day, while open interest counts contracts still outstanding and carries forward until they are closed or expire. High volume with rising open interest points to fresh positioning; high volume with falling open interest points to existing positions being unwound.

Implied volatility is set by supply and demand for each contract separately, so the same strike can price its call and its put differently. Persistent gaps usually reflect directional demand — heavier put buying lifts put implied volatility, producing the downside skew commonly seen in index options. Watching the gap widen or narrow is itself a read on positioning.

The chain behind the page is re-fetched about every 5 seconds in market hours, and the archive is re-read about once a minute. It is a polled reading, not a stream.

The Key terms in the ⓘ button name the colours for each view. Within a strike column the Call bar is always on the left and the Put bar on the right, so the picture does not depend on colour alone.

The marked support is the centre of the strongest scored band of Put Open Interest, weighing size, change and volume, snapped to a strike. The tallest Put bar at or below price among the 15 strikes around the money is the Put wall, shown in the insight's key levels. They can differ.

No snapshot reaches back 15 minutes yet, or the archive has a hole at the boundary. The plane says which. It is not a zero. Choose Day, or wait.

The verdict counts four readings and needs a lead of two. It does not read the bar heights. Open the detail panel to see each reading and its rule.

It is where many Put contracts stand. It does not hold price up by itself. Treat it as a reference and confirm with price.

No. Both read the standing book, so the window does not move them. The Key terms say so.

This page reads the archive of snapshots and its own windows; the chain reads its own polled quotes and its own baselines. The Day comparison in the insight uses the previous close; the chart's Day uses the first reading of the session. Compare the labels and the stamps.

Not on this page: it shows the latest trading session. Chart time steps back within that session. This guide found no date control (see What we have not verified).

No. It places no orders and gives no advice.

Rising open interest at a call strike means fresh call positions are being opened there. When it happens above spot while price is flat or falling, it is usually read as call writing, and that strike tends to act as resistance while the position stays open. The reading reverses if the same strike starts losing open interest quickly, which points to writers stepping away.

A previous-close comparison is dominated by the overnight gap and by positions rolled at the open, which stops being informative within the first hour. Comparing against a snapshot from earlier in the same session isolates what has changed since then, so a build that started at midday is visible instead of being buried under the morning's activity.

A long build-up is price rising together with rising open interest, which points to fresh buying being added. A short build-up is price falling together with rising open interest, pointing to fresh selling. Price rising with falling open interest is short covering, and price falling with falling open interest is long unwinding.

The option chain is re-fetched about every 5 seconds while the market is open; it is polled, not streamed. Greeks and implied volatility are computed from those quotes. Outside market hours the last completed session is shown.

Sahi covers 217 NSE and BSE index and stock F&O underlyings: NSE index options including NIFTY and BANKNIFTY, the NSE stocks in the futures and options segment, and BSE index options such as SENSEX. Every tool works on whichever underlying is selected in the instrument picker, and the selection carries across tools as you move between them.

No account or login is needed. Every tool on this site runs entirely in your browser and is free to use. Nothing you select is stored on a server, and no order can be placed from here — Sahi is an analysis terminal, not a trading or execution platform.

Both. The capsule in the page bar chooses which one a tile leads with, and the second figure shows the other. In the default Build-up colouring, colour follows what the premium and Open Interest did; in Amount colouring it follows the size of the Open Interest.

That many contracts are open at that strike, measured against a maximum chosen by the colour scale. It does not say who holds them or where price will go.

The oldest column of a window has no earlier reading, and a tile whose premium or Open Interest did not move has no clear pattern.

The Overview (the ⓘ button) says tiles compare depth within each wing. In the code the maximum is taken over Calls and Puts together. The Straddle table has its own. See What we have not verified.

The stored readings are re-read about once a minute while the market is open and the page fetches the option chain about every 5 seconds, for the LTP columns and the market line. The tiles are not tick by tick.

A column shows the last reading in its step. The newest one ends at the latest reading, which may be before the step is over.

Not on this page. It draws the latest trading day only.

Support is the Open Interest page's zone rule, snapped to a strike. The Put wall is simply the highest Put Open Interest at or below the price, read within the 15 strikes around spot. They can differ.

No. It names what the premium and Open Interest did together. Open Interest cannot say whether people were buying, writing or hedging.

There is no single good value — put-call ratio is read relative to its own recent range, not against a fixed number. A PCR near 1 suggests balanced call and put open interest. Readings well above the recent range are usually treated as put-heavy positioning, and readings well below as call-heavy. Direction of change matters more than the level.

An OI crossover is the point where total put open interest moves above total call open interest, or falls back below it, flipping which side of the book is heavier. It is the same event as the ratio passing 1.00, which is why it is marked on the PCR line itself. It matters because it marks a change in where the crowd is positioned rather than a change in price. Crossovers around key levels often coincide with a shift in intraday character.

On its own it is context, not a signal. Crossovers are most informative when they line up with something else — price reclaiming a level, a build at a nearby strike, or a shift in max pain. A crossover that happens on thin open interest, or one that reverses within minutes, usually reflects noise in the totals rather than a genuine change in positioning.

Both, and they answer different questions. PCR on total open interest describes the standing book, which moves slowly and reflects accumulated positioning. PCR on change in open interest describes what is being added today and reacts far faster. Intraday reads lean on the change-based ratio; positional reads lean on the total.

Volume counts every contract traded during the session and resets to zero the next day, while open interest counts contracts still outstanding and carries forward until they are closed or expire. High volume with rising open interest points to fresh positioning; high volume with falling open interest points to existing positions being unwound.

No. PCR is a positioning statistic, not a signal — it describes how the option book is arranged, not where price is going. It is most useful as context alongside price structure and the open-interest distribution across strikes. Extreme readings tend to mark crowded positioning, and crowded positioning can persist far longer than expected.

Max Pain is the strike where the total payout to option buyers at expiry is smallest. It is worked from the Open Interest at every strike of the expiry. It is a level read from the book, not a prediction of where price will settle.

No. Max pain is arithmetic on the contracts that are open now, not a prediction of where price must settle. The page itself says it is not a price target or guarantee, and price can move away from it. Whether prices tend to end near it is not something the page tests.

Yes, in words. The Max pain view prints "Spot is above Max Pain" or "Spot is below Max Pain", with the distance in points, in per cent and in strikes away, and the note "A level read from the book, not a prediction". It prints no Bullish or Bearish word. The line is left out when two strikes tie for the lowest total or the chain holds no Open Interest, because there is then no single level to read.

The profile shows the shape around the lowest point, which the single number hides. If the neighbouring strikes are almost as cheap, the floor is shallow and one strike or the next could be called max pain after a small change in the book. If they are much dearer, the floor is sharper.

It is worked again for every reading from the Open Interest of the whole expiry, so it changes whenever the book changes enough for one strike's total to overtake its neighbour's, and it moves a whole strike at a time.

High open interest marks where positioning is concentrated, and those strikes often behave as reference levels — heavy call open interest above spot is commonly read as resistance and heavy put open interest below spot as support. This is a crowding observation, not a rule. Levels can and do break, usually when that open interest unwinds quickly.

An ATM straddle is the combined position of the at-the-money call and put, same strike and expiry, added together. Its combined premium is the options market's own estimate of how much the underlying could move before expiry — a rising premium prices in more movement, a falling one usually reflects time decay, falling implied volatility, or both.

Expected move is 0.85 times the ATM straddle premium, shown as a distance either side of the price. It is a pricing convention, not a probability, not a forecast and not a standard deviation: the Implied Volatility page's 1σ range is a different, larger measure built from implied volatility. It is not a target level and says nothing about whether the underlying stays inside it.

Expected move is the 0.85 × premium convention described above, centred on the price. Breakeven is the wider pair of expiry levels a bought straddle needs to pass to get its premium back: the strike plus or minus the full premium paid, ignoring costs. The two describe different things from the same premium and are shown separately for that reason.

Implied volatility is the annualised movement the option market is currently pricing into a contract, derived by working the Black-Scholes formula backwards from the traded premium. It is an expectation, not a measurement of past movement. When implied volatility rises, premium expands for the same spot price; when it falls, premium contracts.

Premium has three moving parts, and direction is only one of them. If implied volatility drops or enough time passes, the loss from vega and theta can be larger than the gain from delta. This is common right after an event, when implied volatility collapses, and on the final session before expiry, when time value drains fastest.

The option chain is re-fetched about every 5 seconds while the market is open; it is polled, not streamed. Greeks and implied volatility are computed from those quotes. Outside market hours the last completed session is shown.

Gamma exposure is an estimate of how much of the underlying option writers would need to buy or sell to stay hedged as price moves. It multiplies each strike's gamma by the open interest sitting there, scaled so the answer reads as rupees per one per cent move. A large total means hedging flow is large relative to the move that triggers it.

The gamma flip, also called the zero-gamma level, is the price at which the measured net gamma exposure would change sign. Above it the book is measured as net positive and hedging leans against each move; below it the book is net negative and hedging leans with it. This page finds it by recomputing gamma at candidate levels rather than by interpolating the strike profile, because the two methods can disagree by thousands of points on the same tape.

The call gamma wall is the strike above spot carrying the most call-side gamma, and the put gamma wall the strike below spot carrying the most put-side gamma. They are weighted by gamma rather than by contracts, so they can sit on a different strike from the heaviest open-interest strike shown on the Open Interest page — gamma decays with distance from spot, and the two measures answer different questions.

It is weaker here than the American research it comes from. That work assumes dealers are long calls and short puts, which follows from United States customers buying protective puts and writing calls. Indian participant data does not show a stable book of that shape, and index options here are cash settled with heavy expiry-day volume. The absolute gamma reading, which does not assume who holds what, is the part that survives if the convention does not hold.

Open interest and traded premium come from the same session snapshots the rest of this site uses. Gamma is not taken from the feed: it is recomputed per strike from a volatility solved off the traded price, because a strike's call and put must share one gamma and vendor-reported values here do not always agree. Readings are suppressed rather than estimated once a series has settled.

The option chain is re-fetched about every 5 seconds while the market is open; it is polled, not streamed. Greeks and implied volatility are computed from those quotes. Outside market hours the last completed session is shown.

The size of move an option's traded price is paying for, once strike, time to expiry and the underlying's level are accounted for, written as a yearly percentage. Higher IV means dearer options. It says how big a move is priced, never which way — IV can rise in a falling market and in a rising one.

Compare it with the same underlying's own past year. IV Percentile is the share of the last 252 sessions whose IV closed below today's; IV Rank is where today sits between the year's lowest and highest close. At 80 or more this page calls IV high for its year, at 20 or less low. The year is measured on a steady 30-day IV, because the front weekly expiry's IV climbs into every expiry day and would rank the day of the week instead of the volatility.

Multiply the underlying's level by the IV and by the square root of the calendar days to expiry over 365. That is one standard deviation: the pricing model puts about two outcomes in three inside it, and it says nothing about which side. Divide it by the square root of the trading sessions left and you have the move priced for one day. The page prints both, with the range they span.

One fair test is the underlying's own recent days. The page sets the move priced for one day beside the underlying's typical day over its last 20 sessions (its historical volatility, from daily closes), both in points. Priced for bigger days than the market has been having reads as dear; smaller, as cheap. It only names a side when the gap is over 20%, because a 20-session figure is itself uncertain by about 16%.

IV counts calendar days to expiry, as India VIX and brokers do, but the market only moves on trading days. Friday's price spreads two sessions over four calendar days; Monday's spreads one over one — so Monday's IV reads several points higher with nothing having happened. The move priced per day, in points, carries no calendar, which is why the page also compares today with the previous close that way.

India VIX is NSE's 30-day index built from NIFTY's near and next month options across every strike. Out-of-the-money PUTs carry more volatility than the at-the-money strike, so VIX usually reads about a point above an at-the-money 30-day IV. The page shows it beside NIFTY's own figures as a yardstick, not as the same number.

Because with the correct centre they should. Put-call parity is an arbitrage relationship, not a model, and it means one volatility reprices both legs of a strike. Where two figures disagree at one strike, the gap measures stale quotes or an off-centre calculation, so this page lists it among its calculations as a data check rather than as a signal.

An open interest spurt is an unusually fast change in outstanding contracts over a short measured window. It draws attention to strikes where positioning is changing more quickly than the surrounding book. The price move alongside that open-interest change is still needed to distinguish fresh long or short positioning from covering and unwinding.

Read each point by both axes rather than by its colour alone. Horizontal movement shows the option premium change and vertical movement shows the open-interest change over the selected window. A trail reveals how the contract reached its current quadrant, while the detail panel identifies the strike, option side and figures behind that path.

A long build-up is price rising together with rising open interest, which points to fresh buying being added. A short build-up is price falling together with rising open interest, pointing to fresh selling. Price rising with falling open interest is short covering, and price falling with falling open interest is long unwinding.

Volume counts every contract traded during the session and resets to zero the next day, while open interest counts contracts still outstanding and carries forward until they are closed or expire. High volume with rising open interest points to fresh positioning; high volume with falling open interest points to existing positions being unwound.

The option chain is re-fetched about every 5 seconds while the market is open; it is polled, not streamed. Greeks and implied volatility are computed from those quotes. Outside market hours the last completed session is shown.

No account or login is needed. Every tool on this site runs entirely in your browser and is free to use. Nothing you select is stored on a server, and no order can be placed from here — Sahi is an analysis terminal, not a trading or execution platform.

An options strategy builder combines individual option positions into one view of potential profit, loss and exposure. Each leg has its own contract, direction, quantity and entry price. The combined payoff helps you compare structures, locate breakevens and understand where a position has limited or unlimited risk before placing any orders.

An expiry payoff uses each option's intrinsic value at a chosen settlement price, together with the entered premiums and quantities. Before expiry, options can retain time value, so a target-date estimate needs a pricing model and assumptions about volatility and time remaining. That estimate can change even when the underlying price is unchanged.

Displayed premiums are reference quotes or the entry prices you enter. They do not guarantee a fill. Actual execution depends on the available bid and ask, order quantity, liquidity and market movement. Check the quote timestamp and your broker's current order book, charges and margin requirements when evaluating a position for execution.

Building a strategy is an analysis action and does not place an order. Adding, removing or editing legs changes the simulated position and its calculations. Use the resulting payoff and scenarios to examine the structure, then make any separate execution decision through your broker after checking the current contracts, prices and account requirements.

Contracts lists individual options and answers where the action is: what moved, where positions opened or closed and where money traded. Underlyings reads each stock or index through its options and futures. Custom lists contracts or underlyings that meet conditions you set, joined by All or Any. None of the three predicts price; each describes what the market did.

Chance worthless is the model's chance that an option ends out of the money at expiry: a Call at or below its strike, a Put at or above it. It is read from the expiry's implied volatility smile, centred on the price its Calls and Puts imply for expiry, using the market's own prices. It is a model reading, not a forecast of what will happen.

A percentage on a tiny base misleads: 2 lots growing to 60 is up 2,900%, yet it is only 58 lots. The Starting Open Interest floor, 50 lots by default, keeps the open interest percentage scans and Volume above Open Interest to contracts that began with a real position. Read the lots first, then the percentage, which says how fast the change arrived.

No. The scanner lists and describes options and places no orders, and its lists stay on the page. Opening a row shows that contract's chain studio for inspection. Quote time, liquidity, charges and margin need to be checked separately before any execution decision made elsewhere, and nothing here is a recommendation.

From the future, not the spot: the near-month future's price change over the window, with open interest summed over every listed month so a position rolled to the next month does not read as closed. A move past the floor, half a percent on the day by default, takes a side; a smaller move is flat. The side is a state the market is in, not a forecast of where it goes next.

The fifteen-minute stretch of the session's futures candles in which the most open interest was added while the price moved the side's way, shown as the price range of that stretch and the clock. It says where positions were opened fastest. It does not say who opened them, and open interest cannot.

Each side is ranked by the size of the move, futures readings first. Strength is a separate standing within the side: how far it moved against the others, how much open interest moved with it (positions opened count in full, positions closed at half), and how many of five checks hold. The strongest positions opened with the move become the big cards.

No. It sorts and describes what the futures and options did, and places no orders. Possible support and resistance are the heaviest Put and Call open interest either side of spot on the nearest live expiry, named as what they are; nothing here is a recommendation.

The Trader Cockpit is a page on which you place the app’s tools, such as the option chain, Open Interest, the Put Call Ratio, the straddle and implied volatility, as widgets that share one symbol and one expiry. There are 28 widgets, and you arrange them into named layouts that fill the window. It adds no new market data and places no orders.

On this device, in this browser’s storage, and nowhere else. There is no account and no sign-in. Layouts survive a reload, a new tab and a restart, and are forgotten if you clear the site’s data or use a private window. If the saved layouts cannot be read, the old data is copied aside in the same browser, the Market desk layout opens and a one-line notice says so.

Yes, as text. Sahi hands out no files, so there is no file export. Use View, Copy layout as text, in one browser, and View, Paste a layout, in the other; the layout opens there as a new layout. The widgets’ own Customise choices do not travel with it.

Up to 12 named layouts in a browser, each widget at most once per layout, from a catalogue of 28. Only the first ten layouts have a number key (Ctrl + Alt + 1 to 9, and 0 for the tenth).

Yes. The symbol and the expiry are shared, so changing them once, from the toolbar, the command palette, the symbol picker or any widget’s header chip, updates every widget. There is no per-widget symbol. Each widget keeps its own view and its own Customise choices.

Fit, or the T key, packs every widget of the open layout into even rows that fill the screen, giving up height before width. Undo puts the layout back. Auto-fit in the View menu does the same after every add, remove and resize. Fit replaced the earlier Tidy up.

The rows are worked out so that the layout fills the window exactly: they grow on a tall screen and shrink on a short one, down to 24 pixels, before anything scrolls. The layout itself is kept in columns and rows, so it is the same arrangement on any screen.

It is the price of the underlying that the Call and Put prices of the open expiry imply, worked out from option prices. It is not a futures quote, and the Cockpit reads no futures price in its own readings.

While the session runs, the data line compares the clock with the time of the chain’s snapshot: up to 90 seconds old reads Live, up to 600 seconds Delayed, and older Stale. When the market is closed it reads Closing data and the time, for example Closing data · 19 Oct, 15:40 IST, because the last close is the current reading. A saved session reads Saved session.

By the same rule as the Open Interest page and the Option Chain: within the 15 strikes around the money (the ATM strike and 7 listed strikes on each side), the Call wall is the strike at or above spot with the most Call Open Interest and the Put wall the strike at or below spot with the most Put Open Interest. A wall is not the same as a gamma wall.

They count different strikes, and each prints its scope beside the figure. The strip counts the whole expiry; the PCR chart counts the strikes around the money chosen in the PCR page’s Customise, ATM ±20 by default. On one reading of NIFTY after the close on 19 Oct they read 0.88 (whole expiry) and 0.92 (ATM ±20, 41 strikes).

Only the Straddle ladder, Build-up movers and the Open Interest change leaderboard. Picking a strike in one marks it in the others that follow. The crosshair toggle inside each one’s header chip turns following off or on, and the choice is remembered for that widget. The shared strike is dropped when the symbol or the expiry changes.

Ctrl or Cmd K opens the command palette, in Focus mode too, and the slash key opens it on symbols. T fits the layout to the screen, L locks it, Shift T opens All layouts, [ and ] step between layouts, and Ctrl + Alt + 1 to 9 switch to a layout. Ctrl or Cmd Z undoes up to 50 changes and Ctrl Shift Z or Ctrl Y does them again. Ctrl + Alt + A opens Add widget, Ctrl + Alt + F turns Focus mode on or off, and M maximises a widget while Esc restores it. A question mark, or Keyboard shortcuts in the View menu, shows the full list, which the app prints from the same table that runs the keys. Plain letters other than T, L and M start the symbol picker, and plain numbers switch workspaces. The keys are off while you type in a box.

One box, opened with Ctrl or Cmd K or the Search button, that finds symbols, widgets, layouts and actions. Results are grouped as Recent, Symbols, Widgets, Layouts and Actions. A prefix narrows it: > for actions, @ for symbols, + for widgets and # for layouts. A row that cannot run, such as Fit to screen on a layout already fitted, stays in the list and says why. The palette is a desktop control; on a phone use the symbol button and the sheets.

A browser with nothing saved opens straight onto the Market desk layout and saves it. A strip under the toolbar, Start with a layout, offers 6 layouts as small drawings, with More layouts for the full gallery and a button to dismiss it. There is no welcome page. The strip is for the first visit only, and your first change to the layout closes it.

Maximise it: press the button in its header (in the ⋯ menu on a touch screen), double-click the empty part of its header, or press M. Esc, M or the same button restores it. The other widgets are set aside until you restore. For a lasting change of size, use the Size menu: Small, Medium, Large, Full width or Full height.

Yes. Tab to a widget’s grip and press the arrow keys to move it one cell at a time; hold Shift with the arrow keys to resize it, one column or one row per press. The new position or size is announced to a screen reader. Both are off while the layout is locked.

Less than you might expect. On the desktop grid a widget is opened only when it comes near the visible canvas, is shown once it has settled, and then keeps its state. On a phone only the open tab’s widget is mounted at all.

At 768 pixels or less it shows one tab per widget instead of a grid. A one-row header holds the layout name, the symbol, the expiry and a More button; the open widget fills the screen and is the only one mounted; and a bottom bar holds the widget tabs, an N of M counter and Add. Layouts, More and Add open as sheets. You can swipe between tabs, and Undo and Redo appear under the header. There is no grid, Fit, Size menu or Focus mode on a phone. Between 769 to 1100 px the layout is shown in two columns, without changing the saved desktop layout.

No. It is an analysis screen. It places no order, sets no alert and gives no advice, and no level or word on it is a forecast.

No. Lock removes dragging, resizing, the Size menu and the remove buttons, and switches off the Delete key, Fit and the Ctrl + Alt + A shortcut. The Add widget panel, maximise and the layout menu still work.

Up to 50 changes to a layout: adding, moving, resizing and removing a widget, a size from the Size menu, Fit, Clear all widgets and a ready-made layout used with Reset this layout to. Redo does an undone change again. It cannot undo a deleted layout, a rename, a View choice or a change of symbol, and the history is forgotten on a reload.

The toolbar says Market open, with the time left to the 15:40 close, only while the derivatives session runs, from 9:15. At any other time it says Market closed, with Closing data and the time of the last reading. The times are the app’s own settings.

The pictures use an invented market made for the guide, so their figures are not prices. A few figures, marked in the guide, come from one reading of NIFTY after the close on 19 Oct. All of them show how the Cockpit works, not what the market will do.

No tab or page has that name. The feature is the Insight card above the Option Chain, opened with View insight. It is a fixed rule, not a trained model.

When positioning has no lean (a bullish share between 40% and 60%), or the index is within 0.05% of its previous close, or the two comparisons point opposite ways.

The chosen window has no matched earlier reading, fewer than 60% of displayed legs are matched, fewer than 2 legs are matched, or only Calls or only Puts were measured.

An index opens on 15 min and a stock on Day. Your choice is remembered separately for indices and stocks.

No. It says that positioning on the displayed strikes and the index change agree at this moment. Open Interest does not show who opened a position or why.

Dozens on either side of spot — a full chain including the wings commonly runs past eighty rows in total. The exchange lists strikes on a grid and extends it outward as the index travels, so the count grows on a trending day. What matters more than the count is that open interest is spread across most of those rows rather than clustered in a handful near the money.

Near-the-money strikes are listed about 50 points apart, which is roughly 0.20% of the index at current levels. The exchange sets that grid and extends it as spot moves, and spacing is generally wider on strikes far from the money. Treat it as the grid you can see on the chain today rather than a permanent property of the contract.

No — they are cash-settled. Nothing is delivered and no stock position appears in your account. At expiry the contract pays a rupee difference computed against the settlement value the exchange publishes for the expiry day it has set. That also means no assignment risk in the equity sense, and no repricing from any single constituent's corporate action.

Because the participant base behind it is broader. Index option flow in India concentrates on this contract, portfolio hedging naturally reaches for strikes some distance from spot, and systematic premium-selling programmes populate the wings continuously. None of those activities needs a directional view, so open interest persists at far strikes instead of draining away between events.

It is commonly read that way, and it is a crowding observation rather than a rule. Heavy call open interest marks where writers have positioned, not a level price must respect — those levels break regularly, and often precisely because everyone was watching them. Open interest also counts contracts rather than opinions, so hedging can build the same number.

Both, and preferably side by side. The near-dated series carries most of the day's volume and reacts fastest to spot, so it describes intraday tone. The monthly carries a much larger standing base built over weeks and describes positional context. Reading one alone makes an ordinary roll between series look like positions being abandoned.

Two separate reasons stack on top of each other. The index trades above twice NIFTY's level, so any percentage move is worth more than twice as many points, and points are what premium is quoted in. On top of that, a concentrated banking index prices a somewhat wider percentage move — around 1.15% against roughly 0.90%. Only the percentage figure is comparable.

Wider than the roughly 50-point grid used near the money on NIFTY, because 50 points on an index near 55000 would be under a tenth of a per cent and would produce an unreadable chain. The exchange sets the grid and extends it outward as spot travels. In percentage terms the two grids are close; in points, each BANKNIFTY step is a far larger gap.

Because it holds far fewer names and every one of them is a bank. They share a rate cycle, a credit cycle, a regulator and a deposit market, so news touching the sector touches every constituent in the same direction at once. A fifty-stock benchmark spread across sectors dilutes the same news across companies that are moving independently.

At the money, yes — it is one of the most heavily traded index option contracts on the exchange. The difference appears once you walk away from spot. Open interest and two-sided quotes thin out faster on the wings than on a broad index, so a far strike's printed last-traded price may not be a price you can actually transact at.

Not usefully. PCR has no absolute scale and no shared neutral point across underlyings, because each one carries its own mix of hedgers and speculators. Compare a reading against that instrument's own recent range instead, and treat the direction of travel within the range as the observation rather than the level itself.

No. A larger premium is the market's price for a wider expected move, and both sides transact at a price that already reflects it. What scales with the index level is the size of every number involved — the premium, the daily decay in rupees, and the loss an adverse move produces. None of that is an edge for the buyer or for the writer.

SENSEX options are listed, matched and cleared on BSE, not NSE. It is the only major index option contract in this set that sits on the other exchange. Its open interest is a separate pool built by BSE participants, and its expiry calendar is set by BSE independently of the NSE one.

Because premium scales with the level of the underlying, and SENSEX trades at more than three times NIFTY. An 800-point SENSEX straddle on an 80200 index and a 245-point NIFTY straddle on a 24500 index are both 1.00% of spot. The rupee figures differ by 3.3 times. What they price is identical.

Near the money the exchange lists SENSEX strikes in hundred-point steps, against fifty points on NIFTY, and it extends and widens that grid as spot travels. Against the index level, though, a hundred points on 80200 is 0.12% while fifty on 24500 is 0.20% — the SENSEX grid is the finer of the two.

No. BSE derivatives volume is smaller than NSE volume, so the SENSEX book is thinner, particularly away from the money. Near-the-money rows quote tightly. Further out, spreads widen faster, a single large position can visibly move strike-level open interest, and distant strikes can carry stale last-traded prices.

Not directly. The exchanges set different contract sizes and revise them, so one contract on each board is a different quantity of index exposure, and the two books have different participants. Compare the shape of the distribution instead — which strikes are heaviest and how fast it falls away — because shape is scale-free.

Because every points-based number on a chain scales with the index it is written on. Strike spacing, premium, spreads, decay and distance to a wall are all larger on a higher index without meaning anything different. Dividing by spot removes the level and leaves what the board is actually pricing.

FINNIFTY is an NSE index of financial services companies, weighted by capped free float. It holds banks alongside insurers, non-bank lenders, housing finance companies and asset managers. That makes it a single-sector index — broader than a banks-only index, and far narrower than the whole-market benchmark it sits inside.

BANKNIFTY holds banks and nothing else, while FINNIFTY adds the rest of financial services — insurers, NBFCs, housing finance and asset managers. The two share their largest constituents, so they agree most of the time. They separate when the non-bank half moves on its own, and that gap is the useful signal.

Fewer participants trade it. It is a sector contract competing for attention with the benchmark and with a banking index that many traders already use as their volatility expression. The result is less open interest at each strike, wider spreads away from the money, and distant strikes that can go untraded for long stretches.

Treat it more cautiously than the same picture on a deeper book. Heavy call open interest above spot is a crowding observation on any underlying, and here the crowd may be small. Check how it accumulated: gradual build with volume beside it is worth more than a single large print far from spot.

The spread is the gap between the highest price a buyer is bidding and the lowest a seller is asking. It is the immediate cost of entering and exiting. A wide spread also makes the mid-price misleading, because no trade happens there — on thin strikes the mid is arithmetic rather than an available price.

It marks where positioning is concentrated, and those strikes often behave as reference levels — heavy calls above spot are commonly read as resistance, heavy puts below as support. This is a crowding observation, not a rule. Levels break, usually when that open interest unwinds quickly.