Any company contemplating an M&A transaction in 2019 might want to take a long, hard second look.

North American deal-making companies lost shareholder value in the second quarter, underperforming the MSCI North American regional index by 3.7 percentage points.

That’s according to Willis Towers Watson’s Quarterly Deal Performance Monitor, run in partnership with the University of London’s Cass Business School. The measurement tracks the percentage change in acquiring companies’ stock prices from six months before deal announcements until the end of the quarters in which deals close.

Results globally were even worse — much worse. For the first time in a decade, companies in every region lost shareholder value after deal announcements, underperforming the MSCI World Index by 6.3 percentage points.

It was an unprecedented seventh consecutive quarter that the global M&A market underperformed.

Asia-Pacific acquirers showed the worst performance of all regions, trailing the market by 7.9 percentage points, followed by European buyers at -4.1 percentage points.

“M&A activity is a barometer of business confidence, and the rapid drop in deal volume in the last six months, especially in the U.S. market, suggests the impact of geopolitical, trade, and tariff uncertainties has been brutal, fueling boardroom uncertainty around the world,” said Duncan Smithson, senior director of mergers and acquisitions for Willis Towers Watson.

For the first time in five years, there were no completed mega-deals (those valued at more than $10 billion) in the second quarter of 2019. North American deal volumes were essentially flat for the quarter.

“Until there is less turbulence in the markets,” Smithson said, “there is a good chance that even fewer deals will be announced in the second half of 2019, underscored by more stringent regulations, protectionism, and political uncertainty continuing to frustrate deal-making.”

Digital disruption will be a major factor shaping the M&A market, according to Smithson, as large companies attempt to assimilate technology to become more efficient and better reach end users by buying boutique firms, resulting in fewer mega-deals.

Only completed M&A deals with a value of at least $100 million were included in the research.