If Suicide Squad were a Marvel Cinematic Universe installment, assuming that the movie has mid-credits and post-credits sequences would have been a no-brainer. Marvel Studios doesn't miss out on using either of the two in their movies.
However, the upcoming August 5 release is a part of the DC Extended Universe, which doesn't have a hard and fast rule about those.
Suicide Squad has already started showing early screenings, and Comic Book confirms that the movie indeed has a mid-credits scene in store for us. Their report reads as follows:
After the credits sequence rolls (that’s also called the “bumper”, the part before the plain black-and-white names and characters part rolls), using the same stylized hyper-colored imagery they've used in the posters and character art, there's one more scene waiting for you on the other side.
The site adds that the mid-credits scene in Suicide Squad is not frivolous, rather it's "pivotal and important". Is there a description of the sequence? Nope! Thankfully, they didn't spoil anything. They just made us aware of the fact that we need to stick to our seats for a while after watching the David Ayer flick!
According to their report, Suicide Squad doesn't have a post-credits sequence. However, we must keep in mind that this report is based on what has been shown at early screenings. So, Warner Bros. may have an after-the-credits scene that they want to keep out of sight until the movie releases officially. Various studios have done it in the past for a number of movies.
Apart from the mid-credits scene confirmation, we have a commercial and a clip, both featuring some new footage from Suicide Squad.
In the TV spot titled Saving The World, Killer Croc makes it clear to the SKWAD that he's "beautiful", while the The Joker has a "neat" medical injection gun in his hand!
The clip, on the other hand, features Boomerang and Slipknot. In it, the former is lecturing the latter on MIND GAMES! Check out the videos below!