what bro

A classic phrase commonly used by people named Kyle or Nikhil, usually indicating a reacting to a question that they do not wish to answer.

the meme you see on almost every youtube video
in other words,
a reporter asked Russell Westbrook a question about his basketball match against the Jazz team and Russell Westbrook responded with "what?! bro what are you talking about man?"

Bro is something you call a "mongrel" or a brother aka your friend... or your greatest enemy if you feel me. But a whatsup means WHAT IS NEW asking your friend/enemy what is new. If a friend, then you are actually asking "whats new" but if its an enemy this jargon is more or less used as a threat as in "whatsup bro, i will tear your spine out you disgusting maniac". People who DO use the term whatsup bro to their friends are deemed mentally and physically insane, and are fit for only one place in this godless world... the highest security mental intitution.

A phrase used when someone says something that's so unbelievably dumb/crazy/weird that you question whether you actually heard it.

Used in the African-American community as an interrogative.
It can also be used to assure someone that what you said is 100% truthful.

A comment to when someone is doing something really fucking stupid

when you encounter a rubbish thing and you're like nah bro what is this bro nah bro what is this bro what bro nah bro