What is a Call Ratio Spread? Definition, Formula, and Example
A call ratio spread is a vertical options strategy that buys one call option and sells a greater number of higher-strike call options to exploit specific skew dynamics.
What is a Call Ratio Spread?
A call ratio spread is a vertical options strategy that involves buying one call option and selling a greater number of higher-strike call options on the same underlying asset with the same expiration date. The standard ratio is 1:2 (buy one call, sell two calls), though 1:3 and 2:3 ratios are common. The strategy is designed to capitalize on implied volatility skew and specific price targets. It is a defined-risk strategy when structured for a net debit, but it carries undefined risk if the underlying asset rallies aggressively past the short strikes.
How it is Calculated and Structured
The profitability of a call ratio spread is determined by the distance between the long and short strikes and the premium collected. The maximum profit occurs if the underlying asset closes exactly at the short strike at expiration. The formula for maximum profit is:
Max Profit = (Long Strike Price - Short Strike Price) × 100 + Net Credit
If the trade is entered for a net debit, the formula adjusts to subtract the debit paid. The upper breakeven is calculated as:
Upper Breakeven = Short Strike + Max Profit / Number of Excess Short Calls
The position combines a long call (bullish) with naked short calls (bearish). The trader pays a debit or collects a credit depending on the width of the strikes and the volatility skew. If the underlying closes below the long strike, the trader loses the initial debit.
Worked Example
Assume NVDA is trading at $120. A trader expects the stock to grind higher but not exceed $130 by Friday. The trader executes a 1:2 call ratio spread:
- Buy 1x NVDA $120 Call for $5.00 ($500 total)
- Sell 2x NVDA $130 Calls for $2.50 each ($500 total)
The trade is opened for a net zero cost. If NVDA closes at exactly $130 at expiration, the long $120 call is worth $1,000. The two short $130 calls expire worthless. The maximum profit is $1,000. However, if NVDA surges to $145, the long call is worth $2,500, but the two short calls are worth $3,000 total. The trader incurs a $500 loss. The upper breakeven is $140.
When Traders Use It
Traders use call ratio spreads when they have a specific price target and expect implied volatility to decrease. The strategy is highly effective when the short strikes are placed at a resistance level or a maximum pain point. It is also used to exploit steep volatility skews where out-of-the-money calls are overpriced relative to at-the-money calls. Market makers and institutional traders use ratio spreads to finance long premium while capping upside risk.
Limitations and Common Misconceptions
A call ratio spread is not a true defined-risk strategy when structured for a net credit. The undefined risk above the short strikes is the primary limitation. Traders often miscalculate the upper breakeven and fail to account for the negative gamma exposure as expiration approaches. A common misconception is that a free trade (zero-cost ratio spread) carries no risk. The risk is entirely concentrated in an aggressive upside rally. Traders must manage the position actively or hedge with further out-of-the-money calls to cap the tail risk.