The buoyant mood of most top CEOs this time last year has shifted dramatically going into 2019. According to a sweeping survey by consulting firm PwC, nearly a third expect growth to decline in coming year.

The Annual Global CEO Survey, conducted this past September and October, and released Monday in anticipation of the first day of the World Economic Forum in Davos, Switzerland, gauges the sentiment among 1,378 chief executives in more than 90 territories and is considered a good indicator of what’s to come in the global economy.

This year’s results are colored by uncertainty brought on by trade wars, political anxieties, slowing growth in several key markets and the likelihood of tighter monetary policy. While 42 percent of CEOs said they still expect economic growth to improve in 2019, 29 percent forecasted a decline, up from just 5 percent last year. The middle ground — those who think growth will remain the same — shrank by 8 percentage points, marking a more polarized group.

Despite Brexit concerns in the U.K. and Europe, the U.S. was the clear nexus of economic anxiety: Optimism among North American CEOs plummeted from 63 percent to 37 percent, while only 27 percent of international CEOs cited the U.S. as a key market for expansion, down from 46 percent last year. While President Donald Trump’s tax cuts kicked the economy into high gear early last year, helping to reduce unemployment and drive consumer spending, those effects are beginning to fade, with many economists predicting a coming downturn.

Looking abroad, Chinese CEOs in particular are planning to reduce their investment in the U.S. in the year ahead — no surprise, given the ongoing trade tensions between the two countries. Only 17 percent of China’s executives cite the U.S. as a growth market for 2019, down from 59 percent last year. (Australia, barely a blip on the radar last year, is now China’s top market for growth, garnering support from 21 percent of CEOs.)