[U.S. stocks open slightly lower, Novo Nordisk rises over 9%] U.S. stocks opened slightly lower, with the Dow Jones Industrial Average down 0.17%, the S&P 500 Index down 0.08%, and the Nasdaq Composite Index down 0.08%. Novo Nordisk rose 9.5% as the U.S. FDA approved Novo Nordisk's first oral GLP-1 weight-loss drug.