Option Chain Analyzer

Turns a raw NSE option chain JSON into actionable structure.

When to use

• User pastes / fetches option chain data and asks for a read.
• User wants to identify max pain, PCR, or notable OI build-up.
• Pre-market or intraday: "where is BankNifty likely to pin?"

Inputs

Either:

• A JSON dump from NSE's option chain endpoint (https://www.nseindia.com/api/option-chain-indices?symbol=NIFTY), or
• Strike-wise call/put OI + premium tabular data.

Computations

Max pain

Strike at which total OI value (writers' loss) is minimised. Often acts as a magnet near expiry.

max_pain_strike = argmin over K of: sum_i max(K - K_i, 0) * call_OI_i + max(K_i - K, 0) * put_OI_i

PCR (Put-Call Ratio)

PCR_OI = total_put_OI / total_call_OI

• > 1.3 → oversold / bullish reversal zone (contrarian read)
• < 0.7 → overbought / bearish reversal zone
• 0.8–1.2 → neutral

Support / Resistance from OI

• Strongest resistance = strike with highest call OI above spot.
• Strongest support = strike with highest put OI below spot.

OI build-up classification

IV skew

Compare ATM call IV vs ATM put IV. Put IV > call IV → fear premium. Useful for direction bias before events.

Output format

Return a structured summary:

Spot: 24,150
Max pain: 24,200 (likely pin near expiry)
PCR (OI): 1.18 → mildly bullish
Resistance: 24,300 CE (highest call OI)
Support: 24,000 PE (highest put OI)
Notable build-up:
  - 24,500 CE: short build-up (+3.2L OI, premium ↓)
  - 23,900 PE: long build-up (+2.1L OI, premium ↑)

Caveats

• NSE data has ~3 min lag; max pain is a tendency, not a guarantee.
• On expiry day, max pain pull strengthens after 1 PM IST.
• Always check FII/DII data alongside — OI alone misses positioning context.