NEW YORK — The U.S. Dollar Index logged its steepest six-month drop in more than 50 years during the first half of 2025, falling about 10% against other major currencies since President Donald Trump returned to the White House. The dollar has declined by roughly 10% to 17% against currencies including the Swiss franc, South African rand, Danish krone, Swedish krona and the euro.

U.S. presidents have long voiced support for a strong dollar even as they pursued policies that at times pushed the currency lower. Trump has suggested that a strong dollar puts the country at a disadvantage and that a weak dollar helps American industry. "You make a hell of a lot more money with a weaker dollar," Trump said.

A strong dollar makes imports cheaper and can help keep inflation in check, while a weak dollar can increase prices on foreign goods and boost American exports. For big multinational companies that do business overseas, a weaker dollar can spur sales for products that become cheaper. Executives at companies including Philip Morris and Coca-Cola have described a weaker dollar as providing a "favorable currency impact" that added to their bottom lines.

Most U.S. businesses do not operate internationally, and smaller businesses are often more susceptible to currency fluctuations than larger companies. Consumers may feel the impact through higher prices on imported goods, said Thomas Savidge, an economist at the American Institute for Economic Research. "It's kind of a hidden tax. What your dollar is going to be able to buy is going to shrink," Savidge said.

Brazil is the biggest source of coffee for the U.S., and the dollar has fallen around 13% against the Brazilian real. Coffee prices in the U.S. have increased nearly 19% in the past year, according to government data. When crossing into Mexico, the dollar is about 16% weaker against the peso compared with early 2025.

Kenneth Rogoff, a Harvard University economist and former chief economist at the International Monetary Fund, said the currency's slide may continue. "The dollar had been on a 15-year bull run. I would argue the dollar is still wildly overvalued, and over the next maybe five or six years, it might fall 15%," Rogoff said. He said commodity prices are likely to rise, citing the Iran war's impact on fuel prices. "They're just going to go up no matter what the dollar's at," he said.