Is bitcoin a leading indicator for the stock market? - MarketWatch illustration/iStockphoto U.S. stocks staged a furious comeback rally on Friday as investors once again swooped in to buy the dip ahead of the weekend. Bitcoin prices, on the other hand, continued to sink. The rebound helped save the Nasdaq Composite COMP from what would have been its worst weekly percentage-point decline since April. But the index still tallied a third-straight weekly decline, while the S&P 500 SPX and Dow Jones Industria ...