When running a calendar spread with calls, you’re selling and buying a call with the same strike price, but the call you buy will have a later expiration date than the call you sell. You’re taking advantage of accelerating time decay on the front-month (shorter-term) call as expiration approaches. Just before front-month expiration, you want to buy back the shorter-term call for next to nothing. At the same time, you will sell the back-month call to close your position. Ideally, the back-month call will still have significant time value.
If you’re anticipating minimal movement on the stock, construct your calendar spread with at-the-money calls. If you’re mildly bullish, use slightly out-of-the-money calls. This can give you a lower up-front cost.
Because the front-month and back-month options both have the same strike price, you can’t capture any intrinsic value on the options. You can only capture time value. However, as the calls get deep in-the-money or far out-of-the-money, time value will begin to disappear. Time value is maximized with at-the-money options, so you need the stock price to stay as close to strike A as possible.
For this Playbook, I’m using the example of a one-month calendar spread. But please note it is possible to use different time intervals. If you’re going to use more than a one-month interval between the front-month and back-month options, you need to understand the ins and outs of rolling an option position.