What did you do?

[Rachel Adams]

Why is the "do" stressed in the question? Is "did" also stressed and are all auxiliary verbs usually stressed in questions and negative sentences?

It starts at 0:53

 

[Ostap]

Maybe just his way of speaking? I don't think there's anything grammatical about that. He also puts noticeable stress on "more" and "money" at 0:26.
No, "did" is not stressed here.