Stocks slumped on Wall Street, yesterday, hit by a poor forecast by the world's biggest retailer, Wal-mart, and as a key report from the Federal Reserve showed a muted picture of US economic growth. So the Dow Jones Industrial Average fell 157 points, or 1%, to close at 16,924. The Nasdaq Composite Index lost 13 points, or 0.3%, to 4,782. And the S&P 500 index shed 9 points, or 0.5%, to 1,994. Wal-Mart Stores sank over 10%, shaving 44 points from the Dow, after the company cut its growth outlook and said it would repurchase 20 billion dollars of its shares over a two-year period as it embarks on a three-year plan to boost growth. In U.S. economic data, retail sales rose 0.1% in September, or less than expected. The Fed's beige book showed a weakening U.S. manufacturing sector, providing further ammunition for those who want the Fed to delay raising interest rates until next year.