A diagonal call spread which involves selling a lower-strike call option and buying a higher-strike call option, with the overall position being executed as a credit. In other words, this position is based on the sale of an at-the-money near-month option and the purchase of an out-of-the-money far-month option.

For example, a trader may sell one XYZ March 50 call and buy one XYZ April 55 call. The lower-strike call, however, can be the near-month option or the far-month option.

The diagonal call bear spread is also referred to as a short diagonal call spread.