This guide explains call and put ratio spreads on Nifty, the numbers on one lot, the risks, how to manage them and how to automate and test them.
At a glance
| Call ratio spread (1×2) | Put ratio spread (1×2) | |
|---|---|---|
| Market view | A modest rise to a target, not a rally | A modest fall to a target, not a crash |
| Legs | Buy 1 call, sell 2 higher calls | Buy 1 put, sell 2 lower puts |
| Cost | Usually a small credit or debit | Usually a small credit or debit |
| Maximum profit | At the short strike | At the short strike |
| Maximum loss | Unlimited above the upper breakeven | Large below the lower breakeven |
| Time decay | Helps | Helps |
| Volatility | A fall in IV helps | A fall in IV helps |
How a ratio spread works
A bull call spread buys one call and sells one higher call. A call ratio spread sells a second higher call. That second call:
- pays for the long call, so the trade costs little or nothing,
- adds to the profit if the index finishes near the short strike, and
- leaves one short call uncovered, so a big rally brings a loss that keeps growing.
The trade suits a view with a target: the index will rise to a level and stop there.
The numbers on a call ratio spread
Using Black–Scholes model prices with Nifty at 25,000, 12 days to expiry, IV of 14% and a lot of 65:
- Buy one 25,000 call at ₹280.50
- Sell two 25,300 calls at ₹150.10 each
- Net credit: ₹19.70 per unit, or ₹1,281 per lot
| Nifty at expiry | P&L per lot |
|---|---|
| 25,000 or lower | +₹1,281 |
| 25,300 | +₹20,781 (maximum) |
| 25,620 | breakeven |
| 25,800 | −₹11,720 |
| 26,000 | −₹24,720 |
Below 25,000 every option expires worthless and you keep the credit. The profit peaks at the 25,300 short strike. Above 25,620 the uncovered call loses ₹65 for every further point. In the model, the chance that Nifty ends above 25,620 is about 19%.
Interactive payoff chart: change the spot, IV, lot size and days to expiry to see the curve, breakevens and Greeks.
The numbers on a put ratio spread
- Buy one 25,000 put at ₹227.10
- Sell two 24,700 puts at ₹113.40 each
- Net debit: ₹0.30 per unit, about ₹20 per lot
| Nifty at expiry | P&L per lot |
|---|---|
| 25,000 or higher | −₹20 |
| 24,700 | +₹19,481 (maximum) |
| 24,400 | breakeven |
| 24,200 | −₹13,020 |
The trade costs almost nothing and pays most at 24,700. A fall below 24,400 starts the loss. In the model, the chance of that is about 15%. Falls in the index tend to be sharper than rises and come with higher volatility, so the uncovered put is the riskier of the two ratio spreads.
How a ratio spread behaves before expiry
The call ratio spread above starts with a delta of about −0.17 per unit, a theta of about +₹645 a day per lot and a vega of about −₹1,023 per lot for each 1-point rise in IV. It earns from time and from falling volatility, and it loses if IV jumps, even before the index reaches the upper breakeven.
The profit at the short strike builds mostly in the last days. A quick move to 25,300 early in the trade shows only a modest gain, because the short calls are still full of time value.
Margin
Because one short option is uncovered, the broker blocks SPAN and exposure margin close to that of a naked short option, minus the benefit of the hedged part. A ratio spread needs far more margin than a bull call spread with the same strikes. Check the amount in your broker's margin calculator before entry, and see the hedge margin benefit.
When a ratio spread works, and when it does not
Works best when:
- You expect a move to a named level and a stall there.
- IV is high, so the two short options pay well.
- Expiry is near, so the short strike's value decays quickly.
Struggles when:
- The index rallies (call ratio) or crashes (put ratio) past the breakeven.
- Volatility rises after entry.
- The move comes on a gap that skips your stop.
Managing a ratio spread
- Set a hard stop at the breakeven. Exit, or buy a further call to cap the risk, if the index reaches the upper breakeven.
- Convert it into a butterfly. Buying one call above the short strike caps the loss and turns the trade into a butterfly spread with uneven wings.
- Take profits near the short strike. The maximum needs an exact finish at expiry.
- Avoid events. A result or policy decision can produce the move a ratio spread cannot handle.
Ratio spread vs a back spread
A back spread reverses the ratio: sell one option near the money and buy two further out. It loses most at the far strike and profits from a large move. A call back spread suits a view that a big rally is coming. It is the opposite trade to the ratio spread in this guide.
Automating a ratio spread
In QuantPower's strategy builder:
- Set the entry condition and the strikes as offsets from ATM, such as buy ATM and sell two 300 points out.
- Place the long option first.
- Add a stop on the index level at the breakeven, not only on P&L, because the loss accelerates past it.
- Add an MTM stop loss and a time exit on expiry day.
Test it in paper trading with a rally and a crash day in the sample.
Backtesting a ratio spread
Include the worst days, not only the average. A ratio spread can show many small wins and one large loss. Test the distance to the short strike, the days to expiry at entry and the stop rule, and judge it by the worst month and the average profit after costs. See avoiding overfitting.
Frequently asked questions
Is a ratio spread risky?
Yes, on one side. The uncovered option has unlimited (call) or very large (put) loss potential beyond the breakeven.
Why trade a ratio spread instead of a vertical spread?
It costs less, often nothing, and pays more if the index finishes at the short strike. The price is the open risk past the breakeven.
What is a 1×2 ratio spread?
One long option and two short options at a further strike, in the same expiry.
How do I limit the risk of a ratio spread?
Buy a further option beyond the short strike, which turns it into a broken-wing butterfly, or use a strict stop at the breakeven.
Sources
- Black, F. and Scholes, M. (1973). The Pricing of Options and Corporate Liabilities. Journal of Political Economy, 81(3), 637–654
- NSE: Equity derivatives contract specifications