A gauge of future U.S. economic activity fell sharply in March, potentially flagging tepid growth this year amid tariffs. The Conference Board said on Monday its Leading Economic Index dropped 0.7% last month after decreasing 0.2% in February. Economists polled by Reuters had forecast the index sliding 0.5%. It fell 1.2% in the six-month period ending in March after contracting 2.3% in the prior six months. "March's decline was concentrated among three components that weakened amid soaring economic uncertainty ahead of pending tariff announcements," said Justyna Zabinska-La Monica, senior manager, business cycle indicators at The Conference Board.