Live NSE option chain — Open Interest, Change in OI, Volume, Implied Volatility and LTP for Calls and Puts at each strike, plus OI buildup (price vs. OI direction) and Max Pain. Indices and a curated list of liquid F&O stocks. Data refreshes roughly every 45 seconds; NSE occasionally rate-limits or blocks this feed, in which case you'll see an "unavailable" notice below instead of stale or fabricated numbers. Greeks (Delta/Gamma/Theta/Vega) are computed locally via Black-Scholes from NSE's own implied volatility, assuming a fixed 7% risk-free rate — not published by NSE itself.