A super annoying and overused phrase that teens or kids often use to say to somebody. It means "that's expected of you". When it's said too many times, it might not make any sense in the way it is used anymore.
A: "I got an A in all my finals!"
B: You would.
A: "Hi! My name is Bob. What's your name?"
B: "lol you would"
A: "I would what.."