The ditch-America trade now has its own acronym: ABUSA

An investment theme is only complete when it gets its own acronym, and the brokers that gave us BRIC, FANG, PIGS and TMT have captured the latest trend perfectly: ABUSA, or Anywhere But U.S.A.

- James Mackintosh

Last week, global stocks made a new all-time high—so long as the U.S. is excluded. True, U.S. stocks rose above where they started the year for the first time since February, on the back of a strong recovery from the post-Liberation Day lows. But being flat for the year isn't much to boast about when stocks elsewhere are up 11% in dollar terms.

The big question for investors is whether U.S. underperformance is just the unwinding of last year's overdone bets on U.S. exceptionalism, or whether the U.S. is beginning a long and painful decline relative to the rest of the world.

My guess is a bit of both, but I'm most confident about the first.

The bet on U.S. exceptionalism was everywhere at the end of last year. As well as the wild excitement about Donald Trump taking the White House again, there was a widespread belief that America had an unassailable lead in innovation, productivity and finance.

U.S. stocks made up two-thirds of the MSCI All-Country World index by value, and all 10 of the world's most valuable companies were American.

The U.S. economy grew way faster than other big industrialized nations over the past five years. And the dollar reached a value not seen since the Plaza Accord to weaken the greenback in 1985. Put another way: Exceptionalism had gone too far.