What to watch, what to trade, and what to avoid on weekly and monthly expiry days. Rollover data, historical expiry-day moves, and current cycle positioning.
Expiry days are the highest-volume, highest-volatility trading days in Indian markets. The dynamics on expiry day are fundamentally different from any other day — positions unwind, gamma exposure compresses, and the option chain anchors to specific strikes. Traders who understand the mechanics make systematic edge; those who don't get chopped up.
Strota's expiry day page covers all four NSE index expiries (NIFTY Thursday, BANK NIFTY Wednesday, FIN NIFTY Tuesday, MIDCAP NIFTY Monday), plus monthly stock futures expiry on the last Thursday. Daily rollover data, the current cycle's positioning, and a historical lookback on how prior expiries played out.
This is an educational and analytical page, not a forecasting service. The point is to make the structure of expiry day visible so you can build your own setup around it.
NIFTY 50 — Thursday. The biggest by volume. Max pain gravity is moderate; pinning to the highest-OI strike is common in the last hour. NIFTY tends to move 0.5-1.2% on a typical expiry day with no special news.
BANK NIFTY — Wednesday. Highest IV among the four. Strongest max pain gravity — BANK NIFTY very often settles within 100-200 points of max pain on Wednesday afternoon. Higher absolute move than NIFTY, often 1.0-2.0% on a typical expiry.
FIN NIFTY — Tuesday. Second-tier liquidity. Max pain gravity weaker than BANK NIFTY because of more diversified underlying. Typical expiry-day move 0.7-1.5%.
MIDCAP NIFTY — Monday. Newest and lowest-liquidity. Max pain gravity weakest of the four. Beta highest, so expiry-day moves can be sharper in percentage terms.
Rollover is the process of closing out the expiring monthly contract and opening a new position in the next month's contract. The rollover percentage is the share of total OI being carried forward to the next month, computed daily in the run-up to monthly expiry.
High rollover (>75%) means traders are confident in their current positioning and willing to hold it into the next month. Usually a sign of strong directional conviction.
Low rollover (<60%) means positions are being closed without being reopened — capitulation or profit-taking, depending on direction of price.
Rollover cost matters too: if the next month's contract trades at a steep premium to the expiring one, it costs traders to roll. High rollover with high cost is a particularly strong conviction signal.
Strota tracks rollover for NIFTY, BANK NIFTY, and each individual F&O stock daily during the last week of each monthly expiry cycle.
Option selling. The classical expiry-day strategy. Sell the strikes immediately above and below spot (ATM straddles, or short strangles a bit wider) in the morning, collect Theta decay through the day, close before settlement. Works best on low-news days; high risk on event days. Strota's option chain shows the strikes with highest IV crush potential.
Pin trades. Bet that the index will close near the highest-OI strike (the 'pin'). Buy the at-the-money straddle if you think the index will not pin (volatility play); sell the OTM strikes around the pin if you think it will.
Avoid: momentum-chasing the first hour. Expiry day morning often sees position-unwind volatility that reverses sharply by midday. The strongest setups emerge after 11 AM.
Strota's expiry-day page surfaces today's max pain, today's highest-OI strikes, the recent move's volatility profile, and the OI-flow signals from the option chain.
Strota's historical lookback shows the close-to-close move on each prior expiry day for the past 50 sessions. Median absolute move on a NIFTY Thursday: 0.6%. On a BANK NIFTY Wednesday: 1.0%. Tail risk is higher than these medians suggest — about 1-in-15 expiry days sees a >2% move, almost always driven by overnight global news or a policy event.
Pattern to watch: monthly expiry weeks see higher absolute moves than weekly-only expiry weeks because monthly OI is much larger. The Monday of monthly expiry week often sets the tone.
Settlement is based on the closing price (the volume-weighted average price of the last 30 minutes of trading: 3:00-3:30 PM IST). All in-the-money option positions auto-exercise at this settlement price.
It's the most popular expiry-day strategy because Theta decay accelerates as time runs out. But Gamma also peaks on expiry day, meaning a sudden move against your position causes losses to compound faster than on any other day. Naked option selling without stops on expiry day has wiped out many retail accounts. Always use spreads, stop losses, or both.
Rollover percentage is the share of expiring monthly OI being rolled into the next month's contract. It's relevant in the last 5-7 trading days of each monthly cycle. Above 75% signals high directional conviction; below 60% signals position closure / capitulation. NSE publishes daily rollover data.
Often, but not always. BANK NIFTY pins to within 100-200 points of max pain on roughly 60-70% of Wednesdays. NIFTY pins within 30-60 points on roughly 55% of Thursdays. Big news days (RBI policy, US Fed announcement, election results, major earnings) override the pin gravity entirely.
Yes — MIDCAP NIFTY weeklies expire Monday, so Monday is an expiry-day trade for that index. For NIFTY and BANK NIFTY, Monday is the start of the new weekly cycle (NIFTY expiring Thursday, BANK NIFTY Wednesday).
Two reasons: BANK NIFTY's underlying is more concentrated (12 banking stocks vs 50 broader stocks) so it has higher realised volatility, and BANK NIFTY weekly options have more open interest leverage than NIFTY's because of higher institutional hedging in the banking sector.