Expiry midday credit spread
By midday on expiry day, out-of-the-money options have very little time left, and many traders see the late morning as a 'theta zone' where their value melts fast. This strategy sells a narrow NIFTY call credit spread about 175 points above the index at 11:00 on the weekly expiry, aims to keep half the credit, and closes within an hour. The bought call caps the loss at the spread's width.How it trades
Results
PRE-BUILT · DEFAULTSWhere it made and lost money
All amounts here are small because the credit is small, but the pattern is clear in this test. Quiet expiry sessions made ₹268 over 18 trades and calm VIX days ₹408 over 12, while choppy days lost ₹1,578 over 17 and days after India VIX closed above 14.5 lost ₹1,150 over 14. A spread 175 points out at midday collects only a few rupees of premium; it keeps that on a quiet day, but on a choppy or nervous day one sharp swing towards the short call lifts the spread's value several times over before the hour is up. Trades taken while NIFTY was below its 20-day average lost ₹1,978 over 24.
About this strategy
- Trade only on the NIFTY weekly expiry day (Tuesday, or the previous session if it is a holiday).
- At 11:00, estimate spot from the expiring chain's put-call parity.
- Sell the call at the strike nearest spot + 175 points and buy the call 50 points above it. One lot each. Other modes sell the put spread, both spreads, or the side against the morning move.
- Take profit once the spread has lost half of the credit received.
- No stop by default: the most the spread can lose is its width minus the credit.
- Close after 60 minutes, or at 13:30, whichever comes first.
Why traders use it
On expiry day, an option 175 points out of the money is very unlikely to finish in the money, and its small remaining premium decays quickly through the middle of the session. A credit spread keeps the risk fixed and the margin low compared with a naked call, and a one-hour hold limits exposure to a late breakout. It is a popular way to trade expiry-day time decay with a small, defined-risk position.
The year in plain words
On NIFTY weekly expiries from 1 Oct 2025 to 30 Sep 2026 with default settings, the strategy sold 52 spreads and won 75% of them before costs, yet lost ₹1,695 (profit factor 0.6). Wins averaged only about ₹65, losses about ₹324, so one loss erased five wins. Thirty-one trades hit the 50% target and 21 closed on time. After ₹20 per order and bid-ask slippage the picture changed completely: the loss grew to ₹6,348 and the win rate fell to 17%, because four orders and the spread on two cheap options cost more than the credit itself in most trades.
What the settings do
Risks
- The credit is often a few rupees per unit, so brokerage and bid-ask spread can exceed it, as the after-costs result shows.
- A fast rally on expiry day can move the short call sharply in minutes, and expiry-day gamma is high.
- A high win rate before costs hides losses that average five times the wins.
- Expiry-day short options carry extra margin, although the bought call offsets most of it.
Who it suits
Traders studying expiry-day time decay with a small, defined-risk position, who want to see how much execution costs matter on cheap options. Capital need is low, but the results call for caution.
Questions traders ask
What is an expiry day credit spread?
It sells an out-of-the-money option on expiry day and buys a further one as protection. The trader keeps the difference in premium if the index stays away from the short strike, and the bought option caps the loss at the gap between the strikes minus the credit.
Is the expiry day midday credit spread profitable?
Not in this backtest. On NIFTY from 1 Oct 2025 to 30 Sep 2026 it lost ₹1,695 before costs and ₹6,348 after ₹20 per order and bid-ask slippage, with statutory charges excluded. Past results do not guarantee future ones.
Why does a 75% win rate still lose money?
The winning trades kept only half of a very small credit, around ₹65 per lot on average, while a losing trade, when the index moved towards the short call, lost about ₹324. Five wins were needed to pay for each loss, and costs then turned most wins into losses.
What is the theta zone on expiry day?
It is a term traders use for the middle of the expiry session, when out-of-the-money options lose their last time value quickly. Selling then aims to capture that decay over a short hold, but the premium left is small and can jump on any sharp move.