Markets make rational calculations. I'm not sure how you could have rationally predicted this. For all I know he'll scrap it all on Monday. It's a bit random.

Hasn't there been too many "Surely they can't be that stupid/incompetent?", starting with "Hillary is surely going to win it"... and until yesterday everyone thought "Surely the regime in charge of the world's biggest economy isn't going to agree to the geriartic-in-a-full-diaper[1] wanting to implement his first-grader logic of how the world economy should work?".

[1] "I’ve heard from a reliable source, that Trump smells of soiled diapers, Axe Body Spray and hotdog burps.": https://www.indy100.com/politics/trump/trump-smell-kinzinger...

Because he is backed by a bunch of billionaires and everyone is trying to figure out why they are shooting themselves in the foot.