Few analysts see its breakout performance
The dollar has been on a tear, with an index tracking it against six other major currencies notching roughly an 8 percent gain since the end of June. Few analysts see its breakout performance stalling out anytime soon since the U.S. economy stands on much firmer footing than most others around the world, Europe's in particular.
For companies in the benchmark S&P 500, that's a big headwind because so many are multinationals, and as a group they derive almost half of their revenue from international markets.
"You will get some companies that have failed to meet expectations based on the weakness we're seeing overseas, so it is going to be a source of disappointment," said Carmine Grigoli, chief investment strategist at Mizuho Securities in New York.
Moreover, that weakness, especially in Europe, "is going to be critical here," he said. "It's an important component of (U.S.) earnings going forward."
And while investors and analysts have begun to figure in the negative effects of a fast-strengthening dollar with regard to the approaching third-quarter reporting period, the risk to the fourth quarter and 2015 remains largely unaccounted for.