A short straddle means selling a call option and a put option with the same strike and the same expiry. The intraday version is opened after the market opens and closed before the market shuts at 15:30 on the same day. It is one of the most widely traded option setups in India, mostly on NIFTY, BANKNIFTY and SENSEX weekly options.
If the terms are new, start with what a straddle is. In short: the call gains when the price rises, the put gains when it falls, and the at-the-money (ATM) strike is the one closest to the current price. Selling both means you collect both premiums and hope the price stays close to the strike.
Intraday profit = straddle price when you sell − straddle price when you buy back
Why the idea works on many days
An ATM option is almost all time value: the part of the premium that pays for the chance of a move before expiry. Time value shrinks every minute, a process called theta decay, and it shrinks fastest in the last few days before expiry. On a calm day, the call and the put both lose value even though NIFTY barely moves, and the seller can buy them back cheaper.
The seller is also usually short implied volatility (IV), the level of fear priced into options. When the morning nerves settle, IV often eases, which lowers both premiums further. Together, time and calmer fear are the two forces working for the seller.
Working against the seller is gamma: when NIFTY runs in one direction, the option on that side gains value faster than the other side loses it. A day that trends 1% or more in one direction is usually a losing day for a short straddle.
A live example: today's NIFTY straddle
The straddle chart below is the clearest way to see whether sellers or buyers are winning today. It plots the ATM call plus the ATM put, one point a minute, with the volume-weighted average price (VWAP) as a dashed line:
If the line is drifting down and staying under its VWAP, the day is behaving like a seller's day. If it has climbed above VWAP and keeps making higher lows, the move is outrunning decay and short straddles opened earlier are under pressure.
A worked example with NIFTY at 25,000
Say it is 09:30 and NIFTY trades at 25,000 with two days left to the weekly expiry. The 25,000 call is ₹110 and the 25,000 put is ₹100. You sell both: the straddle is sold for ₹210. For easy maths, assume one lot is 75 units; lot sizes change, so check the current figure on NSE. The premium collected is ₹210 × 75 = ₹15,750 per lot, but that is not the profit: it is the most you could ever make, and only if NIFTY closes the expiry exactly at 25,000.
A common plan: a stop-loss if the combined premium rises 25% (to about ₹262), otherwise exit at 15:15. Three possible days:
| Kind of day | NIFTY at exit | Straddle at exit | Result per lot |
|---|---|---|---|
| Quiet, range-bound | 25,040 | ₹160 | +₹3,750 |
| Small drift, IV steady | 25,120 | ₹195 | +₹1,125 |
| Trend day, stop hit at 11:40 | 25,230 | ₹262 | −₹3,900 |
| Gap or news shock, stop slips | 25,400 | ₹420 | −₹15,750 |
The intraday numbers are illustrations, not a model: the exact straddle value depends on IV and time left. The pattern is the point. Good days earn a fraction of the premium; a bad day can take back several good days at once, and a stop-loss does not guarantee the exit price when the market jumps.
For comparison, here is the payoff if the same position were held to expiry, where only intrinsic value is left:
| NIFTY at expiry | Call value | Put value | Profit per unit | Per lot of 75 |
|---|---|---|---|---|
| 24,600 | 0 | 400 | −190 | −₹14,250 |
| 24,790 | 0 | 210 | 0 | ₹0 |
| 25,000 | 0 | 0 | +210 | +₹15,750 |
| 25,210 | 210 | 0 | 0 | ₹0 |
| 25,400 | 400 | 0 | −190 | −₹14,250 |
The break-even points are 25,000 ± 210, which is exactly the expected move the options priced in.
Entry: when and which strike
- Time of entry. Many traders avoid the first 15 minutes after 09:15, when spreads are wide and the opening move is still settling. Others wait for the first range to form. There is no correct time; what matters is applying the same rule every day so the results can be judged.
- Strike. The strike nearest to the price at the moment of entry. If NIFTY is between two strikes, the two premiums will differ; some traders pick the strike where call and put are closest in price, so the position starts roughly neutral.
- Expiry. Most intraday sellers use the nearest weekly expiry, because that is where decay is fastest. On expiry day decay is fastest of all, and so is gamma: small moves cause big swings.
Before entering, many traders look at the day's expected range. The live box below turns the ATM straddle into an expected move for NIFTY:
Compare the range with what NIFTY has already moved today. If it has used up most of the expected move by mid-morning, selling more premium is a bet that the move stops.
Stop-losses and exits
Because the risk is open-ended, nearly every intraday seller uses a rule to get out. The three common styles:
- Combined stop-loss. Exit both legs if the straddle price rises a set percentage above the sale price, for example 20% to 30%. Simple, and it ignores harmless swings where one leg rises and the other falls.
- Per-leg stop-loss. Each leg gets its own stop, often 25% to 50% above its sale price. When one leg is stopped, the other stays open and keeps decaying. This can recover part of the loss on a one-way day, but leaves you with a naked option if the market whipsaws back.
- Time exit. Close everything at a fixed time, such as 15:15, so no position is carried overnight by accident.
Read the stop-loss guide for how stop orders fill. In fast markets a stop-loss market order can fill well beyond the trigger, and a stop-loss limit order may not fill at all.
Margin, hedges and position size
Selling options needs margin, and a naked short straddle needs the most. Many traders buy a cheap far call and far put as wings, turning the trade into an iron butterfly. The wings reduce the credit slightly but cap the worst case and usually cut the margin by a large amount. Check the current margin with your broker; rules change.
Position size should start from the loss you can accept on a bad day, not from the premium you hope to earn. If a gap through your stop could cost ₹15,000 per lot, and that is more than you can lose in one day, the position is too big no matter how often the trade has worked.
Common mistakes
- Selling into an event. RBI policy, US inflation data, budget day or big results inside NIFTY can turn a quiet morning into a 1.5% afternoon. Check the economic calendar first.
- Moving the stop-loss further away. The loss that hurts most is the one you refused to take at the planned level.
- Doubling up after a loss. Selling a bigger straddle to win back yesterday's loss multiplies the risk exactly when your judgement is worst.
- Ignoring costs. Four orders a day (or more with adjustments), taxes and slippage take a real share of a small intraday profit. See trading costs.
- Judging the strategy on a few weeks. A run of quiet weeks can make it look safe. Test a rule over many months, including volatile ones, with the backtest page or paper trading first.
The intraday short straddle is a simple trade with a lopsided risk: many small gains and occasional large losses. Treat it as education first, and only risk money you can afford to lose.