Nifty Options Expiry Calendar
The structured schedule that governs when Nifty index option contracts expire, covering both monthly contracts (last Thursday of the month) and weekly contracts (every Thursday) on NSE.
NSE introduced weekly Nifty options in 2016 to complement the longer-standing monthly contracts. Under the monthly regime, each contract expired on the last Thursday of the expiry month; if Thursday was a trading holiday, the preceding Wednesday became the expiry date. Weekly contracts extended this Thursday convention to every week of the calendar, creating up to four or five Nifty option expiries each month.
The practical consequence was a dramatic increase in near-expiry activity. Open interest in the front-week contract historically surged in the 48 hours approaching Thursday, with premium decay (theta) accelerating sharply. Participants observed that Monday-to-Thursday intraday patterns in Nifty often differed in character from the mid-week pattern the following week.
Monthly contracts carried longer time values and were historically preferred for multi-leg positional strategies such as calendar spreads and ratio writes, where time-value cushion mattered. Weekly contracts attracted premium-selling approaches exploiting rapid theta burn, but also attracted speculative directional interest because the absolute premium outlay was lower.
In September 2023, SEBI and NSE rationalised the index options framework: effective from November 2023, only one weekly expiry per index was permitted on any given day to reduce systemic risks from simultaneous multi-index expirations. For Nifty 50, Thursday remained the expiry day; Bank Nifty shifted to Wednesday. This staggering of expiries across the week was intended to distribute settlement-day volatility rather than concentrate it.
The expiry calendar interacted with major data events — RBI policy decisions, Union Budget day, and quarterly earnings — that sometimes coincided with Thursday dates, historically producing elevated implied volatility and option premium spikes in the days preceding those events. Traders tracking the expiry calendar thus aligned it with the macroeconomic event calendar to understand when excess premium might historically have accumulated.