As the Jackson Hole economic summit approaches, the stock market started out Wednesday with another calm day, maintaining its steady course. Jerome Powell, the head of the Federal Reserve, speaks on Friday. The Dow Jones Industrial AverageDJIA +0.06% was down 27 points, or 0.1%, shortly after the opening bell. The Nasdaq CompositeCOMP +0.39% increased by 0.1% while the S&P 500...