Stocks ended lower Friday, giving up early gains after authorities confirmed a second U.S. coronavirus case. The Dow Jones Industrial Average /zigman2/quotes/210598065/realtime DJIA -3.15% fell around 170 points, or 0.6%, to end near 28,990, according to preliminary figures, while the S&P 500 /zigman2/quotes/210599714/realtime SPX -3.03% lost around 30 points, or 0.9%, to finish near 3,295. The Nasdaq Composite /zigman2/quotes/210598365/realtime COMP -2.77% closed near 9,315, off around 88 points, or 0.9%. Analysts said stocks were vulnerable to a pullback as concerns rise about the potential effect of the viral outbreak on global growth. Chinese authorities have moved to restrict movement into and out of several cities, including Wuhan, the center of the outbreak. The spread of the respiratory virus in China and to other countries rattled global markets, fueling fears that the disruption to travel and trade may undermine global economic growth.