Double Diagonal
The strategy
At the outset of this strategy, you’re simultaneously running a diagonal call spread and a diagonal put spread. Both of those strategies are time-decay plays. You’re taking advantage of the fact that the time value of the front-month options decay at a more accelerated rate than the back-month options
At first glance, this seems like an exceptionally complicated option strategy. But if you think of it as capitalizing on minimal stock movement over multiple option expiration cycles, it’s not terribly difficult to understand how it works.
Typically, the stock will be halfway between strike B and strike C when you establish the strategy. If the stock is not in the center at this point, the strategy will have a bullish or bearish bias. You want the stock to remain between strike B and strike C, so the options you’ve sold will expire worthless and you will capture the entire premium. The put you bought at strike A and the call you bought at strike D serve to reduce your risk over the course of the strategy in case the stock makes a larger-than-expected move in either direction.
You should try to establish this strategy for a net credit. But you may not be able to do so because the front-month options you’re selling have less time value than the back-month options you’re buying. So you might choose to run it for a small net debit and make up the cost when you sell the second set of options after front-month expiration.
As expiration of the front-month options approaches, hopefully the stock will be somewhere between strike B and strike C. To complete this strategy, you’ll need to buy to close the front-month options and sell another put at strike B and another call at strike C. These options will have the same expiration as the ones at strike A and strike D. This is known as “rolling” out in time. See rolling an option position for more on this concept.
Most traders buy to close the front-month options before they expire because they don’t want to carry extra risk over the weekend after expiration. This helps guard against unexpected price swings between the close of the market on the expiration date and the open on the following trading day.
Once you’ve sold the additional options at strike B and strike C and all the options have the same expiration date, you’ll discover you’ve gotten yourself into a good old iron condor. The goal at this point is still the same as at the outset—you want the stock price to remain between strike B and C. Ultimately, you want all of the options to expire out-of-the-money and worthless so you can pocket the total credit from running all segments of this strategy.
Some investors consider this to be a nice alternative to simply running a longer-term iron condor, because you can capture the premium for the short options at strike B and C twice.