Weekly Expiry in Indian Markets: Tuesday Nifty, Thursday Sensex

What weekly expiry actually means today

A weekly expiry is the day a weekly options contract stops existing and gets settled. On that day the contract is cash settled against the closing value of its underlying index, and any value left in the option is locked in. After the expiry minute, that specific contract no longer trades. A new weekly contract for the next week is already running alongside it, so there is always a near week contract available.

The single most important fact, and the one most old articles get wrong, is the expiry day. For years the Nifty weekly expiry fell on Thursday, and almost every guide online still says Thursday. That is outdated. After the Securities and Exchange Board of India rationalised expiry days to reduce the crowding of multiple expiries, the National Stock Exchange moved its benchmark Nifty weekly expiry to Tuesday. The Bombay Stock Exchange kept its Sensex weekly expiry on Thursday. So the two big weekly index contracts in India now expire on two different days of the week.

This matters for real money. If you are running a weekly Nifty position thinking it expires Thursday, you may discover on Tuesday afternoon that your entire option has already decayed to its settlement value while you were waiting. Always confirm the live expiry calendar on the exchange website before you place a weekly trade, because exchanges have adjusted these dates more than once and can do so again.

Which contracts still have a weekly expiry

Before November 2024, traders could pick from several weekly index options: Nifty, Bank Nifty, FinNifty, Midcap Nifty on the NSE side, and Sensex and Bankex on the BSE side. SEBI then limited each exchange to one weekly index options contract to curb excessive speculation in short dated options. As a result, the NSE retained only Nifty as its weekly product, and the BSE retained only Sensex.

Bank Nifty, FinNifty and Midcap Nifty lost their weekly contracts and now trade only as monthly options. This was a meaningful change because Bank Nifty weekly options had been one of the most heavily traded instruments in the world by volume. If you still see a strategy that says sell a Bank Nifty weekly straddle, treat it as out of date. Bank Nifty options now expire only on the monthly cycle.

How settlement works on expiry day

Index options in India are European style and cash settled. European style means you cannot exercise early. The option only settles on its expiry day. Cash settled means no shares or index units change hands. The exchange simply pays or collects the difference in rupees between the strike and the final settlement price of the index.

The settlement price is not the last traded tick. For Nifty it is the weighted average of the index over the last half hour of trading on expiry day. This stops a single manipulated print in the final second from deciding the fate of thousands of contracts. If your call strike is below the settlement value, the option is in the money and you receive the difference times the lot size. If it is above, the call expires worthless and the buyer loses the full premium paid.

• In the money options are auto settled. You do not have to do anything to receive your payout.
• Out of the money options expire at zero. A buyer loses the premium, and a seller keeps the premium they collected.
• There is no physical delivery for index options, so you never have to worry about taking delivery of stock on a Nifty or Sensex weekly trade.
• Single stock options are physically settled, which is a different and riskier situation that does not apply to index weekly contracts.

Why premiums collapse: theta and gamma

An option price has two parts: intrinsic value, which is how deep in the money it is, and time value, which is what you pay for the chance that it moves further before expiry. On the morning of expiry day, almost all the time value is still in the premium. By the close, time value must be exactly zero, because there is no more time. This forced collapse of time value is called theta decay, and on the final day it is brutal and fast.

At the same time, the option becomes extremely sensitive to small moves in the index. This sensitivity is called gamma. Near expiry, an at the money option can swing from nearly worthless to several times its value, or the reverse, on a move of just 20 or 30 Nifty points. This is why expiry day looks calm for hours and then produces violent swings in the last hour as the index brushes back and forth across heavily traded strikes.

A worked Nifty weekly example with real rupees

The numbers below are illustrative and chosen to show the mechanics. They are not a recommendation and not a prediction. Suppose it is a Tuesday morning, the Nifty weekly expiry day, and the index is trading near 25,000. A trader expects the index to stay quiet into the close and sells one at the money short straddle: sell the 25,000 call at a premium of 80, and sell the 25,000 put at a premium of 75. The Nifty lot size is 65.

Total premium collected is 80 plus 75, which is 155 points. In rupees that is 155 times 75, which equals Rs 11,625 received up front. This is the most the trader can ever make on this position. The break even points are 25,000 plus 155 on the upside, which is 25,155, and 25,000 minus 155 on the downside, which is 24,845. As long as Nifty settles between 24,845 and 25,155, the trade is profitable.

Now look at two outcomes at the Tuesday close. In the quiet case the index settles at 25,010. The call is worth 10 points and the put is worth nothing. The trader bought back, or had auto settled, 10 points, so the gross profit is 155 minus 10, which is 145 points, or 145 times 75, which is Rs 10,875 gross. In the bad case the index trends up and settles at 25,250. The call is now worth 250 points and the put is worthless. The trader loses 250 minus 155, which is 95 points, or 95 times 75, which is a gross loss of Rs 7,125. A single 250 point move turned a fat winner into a sizeable loss, which is exactly the gamma risk described above.

Costs and taxes that eat into the example

The rupee figures above are gross, before costs. On expiry options the costs are real and you must subtract them. The main statutory cost is the Securities Transaction Tax, which on the sale of options is charged at 0.15% of the premium value on the sell side. In the example the trader sold 155 points across 65 units, a premium value of 155 times 65, which is Rs 10,075, so STT on entry is about Rs 15. If an in the money option is exercised at settlement, STT is also charged on the settlement value, which can be a nasty surprise, so many traders square off in the money options before the close rather than let them expire in the money.

On top of STT there is brokerage, which for discount brokers is commonly a flat fee of around Rs 20 per executed order, plus exchange transaction charges, GST at 18% on brokerage and transaction charges, SEBI turnover fees, and stamp duty on the buy side. For a small two leg straddle the all in cost typically runs to a few hundred rupees. The point is not the exact figure, which depends on your broker, but that you should always reduce the gross profit in the table above by your real round trip cost before judging the trade.

• STT on sold options: 0.15% of the sell side premium value.
• STT on exercised in the money options: charged on the settlement value, an extra cost if you let an in the money option expire.
• Brokerage: often a flat fee per order at discount brokers, charged on both legs and both sides.
• GST at 18% applies on brokerage and on exchange transaction charges, not on the trade value itself.

Weekly versus monthly expiry

Weekly contracts give you a short, sharp window. Theta decay is concentrated, so option buyers must be right quickly and option sellers earn premium fast but carry intense gamma risk near the close. Monthly contracts spread the same decay over four or five weeks, so each day moves the premium less and positions are easier to manage and adjust. The trade off is direct: more frequent weekly expiries mean more decay to harvest but also more decisions, more transaction costs, and more chances to be caught on the wrong side of a sudden move.

Hedgers often prefer monthly options because they want steady protection without re-entering every week. Short term directional traders and premium sellers gravitate to the weekly because the rapid decay suits their style. Neither is better in the abstract. The right choice depends on your holding period, your tolerance for expiry day swings, and how much you are willing to pay in repeated costs.

SEBI rules that shape weekly trading

SEBI tightened the index derivatives framework to protect retail traders who were losing money in short dated options. The headline changes were limiting each exchange to one weekly index options expiry, increasing the minimum contract value so that lot sizes rose, and adding an extra margin on the day of expiry to account for the higher gamma risk. These rules are why Bank Nifty and FinNifty lost their weekly contracts and why a single Nifty lot now controls a larger rupee value than before.

There is also a strict margin regime. You must post SPAN plus exposure margin to carry option short positions, and brokers are required to collect upfront margin. On expiry day brokers may add extra margin and may square off positions that fall short. None of this changes the basic mechanics of expiry, but it changes how much capital you must block and how aggressively a broker can close you out if the market moves against a short position in the final hour.

Common mistakes around expiry

The most common and most expensive mistake in 2026 is using the wrong expiry day. People who learned the market a few years ago still assume Nifty expires Thursday and get caught holding a position that has already settled on Tuesday. Closely related is mixing up the two contracts: Nifty expires Tuesday and Sensex expires Thursday, so a calendar that works for one will be wrong for the other.

The second cluster of mistakes is about risk. Selling naked options on expiry day for a few rupees of premium feels safe until a news headline or a sharp move turns a small credit into a large debit in minutes. Letting an in the money option expire rather than squaring off can trigger extra STT on the settlement value. And over-leveraging, putting on more lots than your account can absorb on a 1% index move, is the single fastest way to blow up a weekly options account.

• Confirm the exact expiry day for the exact contract you are trading. Nifty is Tuesday, Sensex is Thursday.
• Square off in the money options before the close to avoid exercise STT, unless you have deliberately decided otherwise.
• Keep a hard stop loss on every short option position, especially in the volatile final hour.
• Size positions for a realistic adverse move, not for the calm scenario you are hoping for.

Recent expiry day moves to learn from

Expiry days regularly produce large intraday swings because so much open interest is concentrated at round number strikes. The pattern to internalise is that the index often pins near a heavily traded strike for hours, which lulls option sellers into complacency, and then makes a fast directional move in the last hour as those strikes are defended or abandoned. A move of 150 to 300 Nifty points inside a single expiry session is not unusual, and as the worked example showed, a 250 point adverse move was enough to flip a comfortable straddle into a loss.

Rather than memorise any single date, study the option chain on the morning of expiry. Look at where the largest call and put open interest sits, because those strikes act like magnets and like walls. The combined premium of the at the money straddle gives you the market's own estimate of how far the index might move by the close. If that straddle is pricing a 1.5% move and you are selling it, you are betting the real move will be smaller. Confirm everything against the live data on the exchange before you commit capital.

Sources and further reading

For authoritative data and contract specifications, refer to NSE India, the NSE Option Chain, BSE India and SEBI. Expiry days, lot sizes and tax rates do change, so always confirm the current rules and contract details on the official source before you trade. You may also find our notes on volatility and risk management useful alongside this page.

Sources and Further Reading

For authoritative data and further reading on this topic, refer to NSE India, NSE Option Chain and SEBI (Securities and Exchange Board of India). Always confirm current rules, rates and contract specifications on the official source before you trade.