Buy fewer options and sell more at a different strike to create a free or credit trade with asymmetric risk.
A Ratio Spread is an options strategy where you buy a certain number of options at one strike and sell a larger number of options at a different strike, both with the same expiration. The most common ratio is 1:2 -- buy 1 option and sell 2 options at a further-out strike.
The extra option sold (the "naked" leg) generates additional premium, which can reduce the cost of the trade to zero or even create a net credit. However, this naked leg also introduces unlimited risk on one side. The strategy is therefore moderately directional with a defined sweet spot.
Ratio spreads are popular among experienced NSE traders who have a moderately bullish or bearish view and want to enter a trade cheaply. The trade profits handsomely if the underlying moves to the short strike by expiry, but can cause large losses if the move overshoots significantly.
There are two main types: the ratio spread (sell more than you buy) and the ratio backspread (buy more than you sell). Each has a very different risk-reward profile, and understanding the difference is critical before deploying either on live markets.
Buy 1 = ITM or ATM call (e.g., Nifty 24,400 CE)
Sell 2 = OTM calls (e.g., Nifty 24,600 CE x 2)
Net Cost = Premium of 1 bought - Premium of 2 sold (can be debit, zero, or credit)
Upper Breakeven = Higher Strike + Max Profit (per unit)
Risk = Unlimited above upper breakeven (one naked short call)
Maximum profit at the short strike (24,600). Unlimited risk above the upper breakeven. Limited loss below the lower strike.
A put ratio spread is the mirror image: buy 1 higher strike put and sell 2 lower strike puts. For example, buy 1 lot of Nifty 24,600 PE and sell 2 lots of Nifty 24,400 PE. This is used when you have a moderately bearish view and expect Nifty to drop to the 24,400 level but not much further.
The unlimited risk is on the downside. If Nifty crashes below your lower breakeven, the naked short put causes losses that accelerate with every point of decline. This makes put ratio spreads particularly dangerous during black swan events or market crashes.
Nifty is at 24,450. You are moderately bullish and expect Nifty to reach 24,600 by Thursday expiry but not much higher.
Buy 1 lot Nifty 24,400 CE at ₹110 (slightly ITM)
Sell 2 lots Nifty 24,600 CE at ₹30 each = ₹60 received
Net Debit: 110 - 60 = ₹50 per unit = ₹50 x 25 = ₹1,250
Max Profit: (24,600 - 24,400) - 50 = ₹150 per unit = ₹150 x 25 = ₹3,750 (if Nifty closes at exactly 24,600)
Lower Breakeven: 24,400 + 50 = 24,450
Upper Breakeven: 24,600 + 150 = 24,750
Below 24,400: Max loss = ₹1,250 (the net debit)
Above 24,750: Unlimited loss! Every point above 24,750 costs ₹25 per point (1 naked short call).
If Nifty rallies to 25,000 (250 points above upper breakeven): loss = (250 x 25) - 3,750 = ₹2,500. At 25,500 (750 above): loss = (750 x 25) - 3,750 = ₹15,000. The risk accelerates rapidly.
When the premium from the 2 sold options exactly equals the premium of the 1 bought option, you enter for zero cost. Any profit at the sweet spot is pure gain. Popular on Nifty when IV is elevated.
When the 2 sold options generate more premium than the 1 bought option, you receive a net credit. Even if the underlying does not move, you keep the credit. But the unlimited risk side is even more dangerous.
Just because a trade is free to enter does not mean it is risk-free. The unlimited loss potential means the risk-adjusted return may still be unfavorable. Always calculate your upper or lower breakeven carefully.
Despite low or zero cost to enter, SEBI margin rules require full margin for the naked leg. A 1:2 Nifty ratio spread may require ₹1-1.5 lakh in margin for the uncovered short option.
Set a price-based stop-loss. If Nifty crosses your upper breakeven (e.g., 24,750 in our example), immediately close the position or buy back the extra short call. Do not wait and hope. A 500-point gap-up on Monday can cause catastrophic losses.
If the underlying approaches your short strike, buy 1 more call at a higher strike to convert the 1:2 ratio spread into a butterfly. This caps your upside profit but eliminates the unlimited risk. Example: buy 1 lot 24,800 CE to create a 24,400/24,600/24,800 broken-wing butterfly.
If you enter a ratio spread for a weekly expiry, plan to exit by Wednesday afternoon at the latest. Holding into Thursday expiry with a naked leg exposes you to gamma risk and pin risk that can rapidly turn the trade against you.
Zero cost to enter does not mean zero risk. The unlimited loss potential from the naked leg can far exceed any initial investment. Always calculate your breakeven and worst-case scenario before entering.
While the unlimited risk aspect requires experience, ratio backspreads (buy more than sell) have limited risk and can be suitable for intermediate traders. Understand the difference: ratio spread = sell more (unlimited risk), ratio backspread = buy more (limited risk).
While the profit zone may be wide, the tail risk from the unlimited loss side can wipe out months of profits in a single trade. Expected value, not probability alone, determines if a strategy is worth trading.
A 1:2 call ratio spread starts with positive Delta (bullish) but Delta turns negative as the underlying crosses the short strike. The position flips from bullish to bearish above the sweet spot.
Net negative Gamma due to the extra short option. Near the short strike, Gamma risk is highest. Rapid moves against you accelerate losses. This is the most dangerous aspect of ratio spreads.
Net positive Theta when the underlying is near the short strike. The 2 short options decay faster than the 1 long option. Time decay works in your favor in the profit zone.
Net short Vega. Rising IV hurts the position because the 2 short options gain more value than the 1 long option. Enter ratio spreads when IV is elevated and expected to fall.
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