He's also moving a card from one side of his body to another. Later he's moving a card back the other way. My bet is that his vest has some sort of mechanism for moving cards. He moves very awkwardly while doing it, so he's certainly doing some complicated procedure we can't see. He could of course be throwing the card, deflecting it with the insides of his hands or otherwise creating a very curved path, but that's just barely plausible.
Anyway, this guy's Dex score is insane.
He did a demo of his skills at TED: https://www.ted.com/talks/lennart_green_does_close_up_card_m...
For impressive street magic performance, there's Cyril Takayama.
I have been watching a lot of his videos since then. I doubt I'll ever learn to do any of his tricks 100% but I find his commentary on the social aspect of magic very interesting.
The backstory is that the magician in question (Kostya Kimlat) did a trick that Penn & Teller also do, and he did it more or less the same way they do it - except that at the end, at the part where P&T do the sleights that make the trick work, in Kimlat's version the effect was already done because he'd done a different sleight, earlier, about five inches under P&T's noses. It was pretty glorious.
The trick: https://www.youtube.com/watch?v=SCFXV6o7cro
Penn talking about it: https://www.youtube.com/watch?v=MuKail7Jwwg
Edit: I think the actual trick starts at 3:49, when he asks Teller to insert his card, either face up or face down. The move at 4:04 finishes the trick and it's done.
1. a few face-down cards on top to make it look like it's still mixed,
2. all the face-up cards plus Penn's card, which went in face-down,
3. all the face-down cards plus Teller's card, which went in face-up.
That plus they only get half a minute (usually less) of discussion time to figure it out.