Wall Street's weekly performance was near the flat line heading into Friday. Things started OK on the final trading day of the week, until President Donald Trump 's new China trade threats tanked the stock market. The S & P 500 lost 2.71% on Friday — the worst single-session decline since April 10, the day after soaring on the White House pausing "reciprocal" tariffs. For the week, the index sank 2.43%. The Nasdaq also suffered its worst day since April 10, losing 3.56% on Friday. It sank 2.53% for the week ...