Wall Street closes rollercoaster week sharply lower
NEW YORK - US stocks ended sharply lower in a broad sell-off on Friday , ending a week buffeted by strong economic data, corporate tax hike worries, the Delta Covid-19 variant, and possible shifts in the US Federal Reserve's timeline for tapering asset purchases.All three major US stock indexes lost ground, with the Nasdaq Composite Index's weighed down as rising US Treasury yields pressured market-leading growth stocks.They also posted weekly losses, with the S&P index suffering its biggest tw