Maybe, just maybe, Ben Bernanke knows what he's talking about after all.  It's been about one week after the Federal Reserve Chairman said some nice, calming things about the economy, and today, the Dow went up like a rocket. Yes, instead of plunging 300 points, the Dow rose by 497.48 points (or 6.84 percent).  The Nasdaq gained 98.50 points (or a similar 6.76 percent).  This put both indexes into territory not seen since mid-February. A report on home sales in that month ...