The only common factor in all 22 MCU movies in the last 10 years has been the mid and post-credit scenes. 

Giphy

That is about to change with Avengers: Endgame

CNet

Don’t worry. There are no spoilers here. But yeah, for the first time since the inception of the Marvel Cinematic Universe, there will be no post-credit scenes. 

Andrew Plan

And it makes sense. Endgame is the end of Phase 3 of the MCU and will effectively conclude the Infinity Saga. 

So there is nothing left to tease before Phase 4 begins. 

But according to Gamespot, there a bit of an audio stinger at the end, during the time the Marvel logo appears. There is a sound of metal hitting metal, which is open to interpretation but the report suggests that it could be sound of Tony forging first Iron Man armour. 

indieWire

So the choice is yours. You can either sit through the credits to hear that sound or walk off. Personally, I am going to wait till they throw me out of the theatre.