It seems that the editors at yahoo.com were surprised that the worst global markets plunged as a result of the Brexit vote:
Wouldn’t you expect the worst markets to plunge? If you’re a frequent reader of Terribly Write, you’d also expect to find a mistake on the Yahoo! front page. In case it’s one word too many. I think. I’m guessin’ the editors meant: Brexit spurs global markets plunge. Or: Brexit spurs worst global markets plunge. Or something else.