Sahi Guides

Guides to reading option data

10 guides covering every tool on Sahi, plus 4 on the index underlyings themselves — what each number measures, how to read it, and the mistakes that make it misleading. All free, no account needed.

Open the live option chain Options FAQ
Option Chain How to Read an Option Chain Every column of the chain, what it measures, and the order to read them in. Tool: Option Chain Open Interest Open Interest Explained Absolute OI, change, change %, volume and the build-up matrix they combine into. Tool: Option Chain OI Change OI Change Explained What a rising or falling OI number means once you pair it with price. Tool: Option Chain OI Heatmap OI Heatmap Explained Where OI clusters, how walls form, and what the shape of the distribution says. Tool: OI Heatmap PCR PCR Explained What PCR measures, its two variants, why the level alone tells you little, and how to read a crossover. Tool: PCR Max Pain Max Pain Explained The arithmetic behind the strike, and what it does and does not predict. Tool: Option Chain Option Chain ATM Premium & Expected Move What the ATM straddle prices in, and why premium decays the way it does. Tool: Option Chain GEX Levels Gamma Exposure Explained The arithmetic, the flip, the walls — and the assumption underneath all three. Tool: GEX Levels Implied Volatility Implied Volatility Explained How to tell if an IV reading is high — and why platforms disagree about it. Tool: Implied Volatility OI Spurts OI Spurts Explained Spotting a sudden build, and filtering the low-base false positives out. Tool: Option Chain NIFTY NIFTY Options Explained How the benchmark index option contract works, and why its book is the deepest. Underlying: NIFTY BANKNIFTY BANKNIFTY Options Explained Why a concentrated sector index prices wider than the benchmark, and what follows. Underlying: BANKNIFTY SENSEX SENSEX Options Explained The BSE index option, and how to compare it against NSE without being misled. Underlying: SENSEX FINNIFTY FINNIFTY Options Explained Where the financials index sits, and what a thinner book means when you read it. Underlying: FINNIFTY

How these fit together

Start with the option chain — it is the surface every other number is derived from. Open interest and OI change come next, because they are what turns a chain from a price list into a positioning map.

From there the guides split by what they aggregate. The heatmap and max pain read the distribution across strikes. PCR compresses it to one ratio, watches it move, and marks where it crosses. OI spurts look at what changed and how fast.

Those 10 are about method — they apply to any underlying. The 4 index guides are about the contracts themselves: NIFTY, BANKNIFTY, SENSEX, FINNIFTY — how each one is listed, where its liquidity sits, and how it differs from the others. Read a method guide to learn how to read a number; read an index guide to learn what is normal for that underlying.

Guides are method. The per-symbol analysis articles are that method applied to a live book — one for every F&O underlying, rebuilt as the data refreshes. Every answer across all 14 guides is collected in the options FAQ.