Susie James, a retired small business owner in Wales, has observed the recent swings in the stock market with only mild interest. Like many Europeans, Ms. James and her husband hold a significant percentage of their savings in cash, the product of a long-held distrust of the market.

“I’m old enough to have lived through two major crashes,” said Ms. James, 67, recalling the market panic on Black Monday in 1987, when her father lost 10,000 British pounds (about $38,000 today), and the 2008 financial crisis. Her retirement account has earned less than major stock indexes, and to her, investing in the market has brought “just bad experiences.”

Europeans on average save more of their money than Americans, but they have far lower rates of investment in the stock market. While Americans keep only a tenth of their financial assets in cash and low-risk deposits, for Europeans it’s a third, the European Central Bank says.

This conservative approach has insulated many Europeans from the extreme market volatility of recent weeks as President Trump’s tariffs have roiled the global economy. But it has also meant that many have missed out on substantial stock market gains over the long-term, and that the continent has lost out on trillions of dollars in investment, according to Christine Lagarde, the president of the central bank.

About 33 percent of European Union households invest in stocks and investment funds, compared with 51 percent in the United States, according to Bruegel, an economic research institute in Brussels.

And within Europe, there are differences: Rates of investment in stocks, bonds and other traded funds are higher in Scandinavian countries and lower in Spain, France and Italy, three of the continent’s biggest economies, where less than 30 percent of adults invest, according to a 2024 survey conducted by BlackRock and YouGov.