Stock Market

Sterling rallied to a 6 1/2-month high against the dollar on Friday as traders dumped the US currency on speculation that ongoing weakness in the US fiscal position may put the nation's sovereign rating at risk. Broad dollar selling boosted sterling as high as $1.5947, putting the pound on track to post its best weekly performance versus the dollar since early February, although it fell versus the euro, which rallied close to its strongest of the year against the dollar.