American companies spent more than $800 billion on their own shares last year, taking a windfall from deep corporate tax cuts to try to bolster their share prices and improve the look of their quarterly earnings reports.

This year, as the economy’s worsening prospects rattle executives, those buybacks are slowing down. The mood among corporate bosses is likely to stay subdued in the face of the trade war, the broadening impeachment inquiry of President Trump and the 2020 presidential election.

“If you’re at a point where trade and politics are stymieing the ability to plan for the future, I think that that’s another huge factor in terms of how companies are going to spend cash or if they will spend as much cash as they have been,” said Savita Subramanian , head of United States equity strategy at Bank of America Merrill Lynch.

Confidence among chief executives fell to its lowest level in a decade in the third quarter, according to survey data collected by the Conference Board, a nonprofit research group. The last time the survey came close to showing these levels of gloom, businesses were still shedding about 800,000 jobs a month because of the recession.