Selling a credit spread involves selling an option while purchasing a higher or lower strike option (depending on bullish or bearish) with the same expiration and with the short option being more expensive than the long option. For example, selling a put credit spread involves selling a put and buying a lower strike put with the same expiration. Maximum profit would occur if the underlying is trading at or above the sold put strike at expiration; the spread would expire worthless. Selling a call spread involves selling a call and buying a higher strike call with the same expiration. Maximum profit would be realized if the stock is trading at or below the sold call strike at expiration; the spread would expire worthless.
The long options are there to protect the position from the potential losses associated with selling options. With a spread, the most the position can lose is the difference between the strikes minus the initial credit received. This would occur if the stock is trading above at or above the long call or at or below the long put. Using a call credit spread as an example, if a trader sold a 50 call and bought a 55 call, creating a credit of $1, the most the trader can lose is $4 (5 ? 1) if the underlying closed at or above $55.
The Objective
The objective of a credit spread is to profit from the short options? time decay while protecting gains with further out-of-the-money (OTM) long options. The goal is to buy back the spread for less than what it was sold for or not at all (meaning it expires worthless). Just like selling short stock, a trader wants to sell something that is expensive and buy it back for cheaper. The same holds true for credit spreads.
An Example
Here is a credit spread trade idea we recently looked at in . When Amazon Inc. (AMZN) was trading around $348 towards the middle of July, a July 335/340 put spread could have been sold for 0.55. This means the July 340 put strike was sold and the July 335 put strike was purchased for a credit of 0.55. The maximum profit in the spread was the credit received (0.55) and would be realized if AMZN was trading at or above $340 at July expiration. Remember that a profit would be realized if the spread could be bought back (closed out) for less than the credit of 0.55. The most that can be lost on the spread is 4.45 (5 ? 0.55) and that would be realized if the stock was to close at or below $335 at July expiration.
What?s the Point?
The risk/reward ratio of this credit spread begs the question why would anyone want to risk maybe eight times or more on what they stand to make in the example above? The simple answer is probability. Given the ability to repeat the trade over and over again with different outcomes, the trader will make $55 many, many more times than he or she will take the $445 loss. This was a hypothetical situation, but let?s say that the strategies winning percentage was close to 85% like in the example above. The trader needs to look at prior historical price action of the stock to determine probability of success.
Insurance
How does this seem similar to insurance you ask? The credit spread strategy is similar to the insurance business because insurance companies get to keep premiums if people don?t get sick or if people don?t have accidents, etc. Traders turn themselves into something like an insurance company when they implement credit spreads and keep premium as long as something doesn?t go drastically wrong.
Just like an insurance company has to decide if the risk is worth the potential reward, option traders that trade vertical credit spreads have to analyze how much can they collect, how much can they lose and the probability of having a profitable trade. In a future blog, we?ll discuss how a trader can use options implied volatility to help put probability on his or her side.