Reaction to someone doing or saying something that is completely impossible. Unheard of, not realistic or hard to understand.

How Sway? = "How is that possible?"

"How Sway?" was invented by Kanye West during his rant to radio host, Sway.
Please see Kanye West and Sway interview: Raw and Real on Sway in the morning
Kanye repeatedly yells, "How Sway?"
Example #1: Jimmy has no job but is able to pull model chicks with money. How Sway?

Example #2: Donald Trump has no political experience but is leading in the presidential nomination 2016. How Sway?
by Eshaknowsbest April 11, 2016
A phrase used in the context of someone saying something so irrelevant/ignorant that it prompts you to ask them to explain their logic. Credit to Yeezus.
"YG is the king of Compton"
"How Sway?"
by randombeanwisdom August 23, 2016
how the heck, how the fuck.

This was used by Kanye in an interview with Sway.
A: Okay I need you to bring my house to the apartment
A: Sis
by sissssbeforemisssters July 27, 2019
A term combing the words so and way. Meant to sound weird, so you’re friends/ strangers can say “huh”.
“I’m feeling kinda down today”

How sway?”
by Weirdsayings November 10, 2017