NSE F&O study desk

Read the market through open interest.

OI Lens turns NSE end-of-day files and 3-minute intraday snapshots into clear reads: who is building positions, where option writers are defending, how wide the rally or sell-off really is, and which sectors are rotating in.

Built by Susovan Pal for studying the Indian derivatives market. Invite-only. Not investment advice.

Market today23 Oct close · from the app

Nifty 50

22,600

−87.7 (−0.39%)

Breadth score

14 / 100

Washed out · 10% above 50 EMA

Nifty PCR (OI)

0.74

down from 0.82

FII index futures, net

−2.80L

contracts short

Nifty 27 Oct chain · OI by strikecalls · puts

Biggest call wall 23,500 (resistance), biggest put wall 21,500 (support)

213

F&O stocks tracked

497

Nifty 500 stocks in breadth

3 min

intraday snapshot cadence

analysis pages

01 · The whole market

Is the market healthy underneath?

Start wide: how the index is moving, how many stocks are actually taking part, and where money is rotating.

What is the market doing right now?

Market overview

Nifty's intraday path with the advancing vs declining flow underneath it.
Top 10 gainers and losers, each with its futures buildup and % move.
Every sector's buildup mix in one bar: long buildup, short covering, writing, unwinding.

Live every 3 minClosing snapshotEnd of day

How many stocks are really in an uptrend?

Market breadth

Share of Nifty 500 stocks above their 20, 50 and 200-day EMA, with a 0–100 breadth score.
Stocks above vs below each EMA over 3 months, 52-week highs vs lows, advances vs declines.
Nifty 50 vs Midcap 150 vs Smallcap 250 over 1, 3 and 6 months.

498 stocksPlain-language verdict

Which sectors are leading, and which are next?

Sectors and rotation

Sector heatmap cards and the buildup inside each sector, with financials split into PSU banks, private banks, AMCs, insurers, brokers and exchanges.
Sector performance over 1, 3 and 6 months, with the share of stocks above the 50 EMA.
A rotation map (relative strength vs momentum): Leading, Weakening, Lagging, Improving, with weekly tails.

Rotation mapSector filters

02 · Index and derivatives

Where are the big players positioned?

Follow the money in Nifty futures and options, and see what FIIs, DIIs, pros and clients did with it.

Where is Nifty capped, and where is it supported?

Nifty desk

Futures across all expiries: price, OI, buildup, PCR and ATM IV, with a 10-session strip.
This week's and next expiry's option chains, 20 strikes either side, with the biggest call and put walls marked.
OI change history and buildup history by strike, plus a verdict and trade setups built from the numbers.

Two option chainsWalls and max pain

Who added longs or shorts yesterday?

FII / DII positions

Net index futures, calls and puts for FII, DII, PRO and Client over 10 sessions.
A who-did-what board: opened fresh shorts, covered shorts, added longs, exited longs.
A written read of the session each evening, downloadable as a PDF.

Evening write-upPDF

Are option writers defending a level?

Options activity

For every F&O stock: are calls and puts being written, bought, covered or unwound?
A positioning ladder (calls left, puts right), put and call walls, and trapped writers.
Unusual strikes by distance from spot and premium moved, plus bullish and bearish setups with their checks.

Unusual strikesSetups

03 · Stocks

Which stocks have real conviction behind them?

Screen every F&O stock on futures positioning, options, technicals and a single strength score, then open any stock for the full story.

Who is building positions in each stock?

Futures buildup and 10-day trend

Long buildup, short buildup, short covering or long unwinding for all 213 F&O stocks, with OI %, volume × and PCR.
Unusual activity: OI moves of 5%+ on 1.5× normal volume.
A side drawer per stock with 10 sessions of buildup, charts, the option chain and a daily / 1-hour chart pop-up.

Live every 3 minUnusual flags

Is this stock strong or weak, all things considered?

Stock page and overall strength

Search any F&O stock, or browse them by sector, by buildup or by strength.
Quick read cards, a 6-month synced timeline, option walls and the full option chain, live during the session.
A 13-point checklist (trend, RSI, buildup, basis, PCR, IV, walls, delivery, volume) rolled into one −100 to +100 score, with ⚡ sudden-change flags.

Strength scoreSudden changes

Where do the charts line up?

Technical scan

EMA 20/50/200, RSI and MACD on 15-minute, 1-hour and daily candles, rolled into one technical score.
EMA 20/50 pullback scans for buys and sells, on daily and 1-hour charts.
52-week range, support and resistance, chart patterns, setup cards and a strength map.

3 timeframesPullback scans

Is there a clean entry on the 1-hour chart?

Swing signals

1-hour EMA 20/50 pullbacks in the direction of the trend.
Buys only above the 200 EMA, sells only below it.
Each signal shows the checks it passed: ribbon, pullback, trigger, volume and RSI.

Checked hourly

Who reports results soon, and how are they positioned?

Results calendar and reports

Upcoming and past board meetings for every F&O stock.
A pre-earnings report per stock: futures, options, delivery and IV going into the print, written up by Claude.
Reports download as PDF.

Pre-earnings PDF

04 · How to read it

The four ideas behind every page

You don't need to know them all on day one. These four come up on almost every screen.

Buildup in 10 seconds

Compare today's futures price change with the change in open interest (open positions).

Option walls

The strike with the most call OI above the price acts as resistance; the most put OI below acts as support. Walls moving up is bullish.

PCR

Put-call ratio of open interest. Rising PCR means puts are being written: traders expect support. Below 0.7 is call-heavy.

IV

Implied volatility: how expensive options are. IV falling on an up day means fear easing; rising on a down day, fear rising.

Strength score

Each stock's checklist adds up: bullish checks minus bearish checks, scaled to −100…+100. ⚡ marks a swing of 40+ points since yesterday.

05 · Your day

How a day works

The desk follows the NSE session, then settles on the exchange's final numbers in the evening.

9:15 am
Live pages start refreshing from 3-minute futures, options and price snapshots.
3:30 pm
The closing snapshot holds the last intraday picture until the exchange files land.
Evening
End-of-day OI, candles and FII/DII data load, and pages switch to the final numbers.
After EOD
The FII/DII write-up and pre-earnings reports are written for the session.