U.S. stocks surrendered early gains on Tuesday after a weaker-than-expected reading on the nation’s services sector reinforced concerns about slowing growth and trade friction. The July Institute for Supply Management non-manufacturing index slipped to 50.1, falling below both the consensus forecast of 51.5 and June’s 50.8. A reading just above 50 indicates that the sector is barely expanding. The disappointing data, combined with fresh threats from President Donald Trump to impose tariffs on imported semiconductors and pharmaceuticals “within the next week,” sent major equity benchmarks into the red. By mid-afternoon in New York, the S&P 500 and Nasdaq Composite were each down roughly 0.5%, while the Dow Jones Industrial Average also turned negative. Treasury yields eased ahead of a $58 billion three-year note auction as traders trimmed expectations for economic momentum.