 The major US stock indices are moving lower at the open as tighter central-bank policy has traders worried about growth.Dow Industrial Average is trading down -377 points or -1.12 at 33583SP index is down -54.2 or -1.35 at 3941.06NASDAQ index down -185 points or -1.66 at 10983Russell 2000 index down -24 points more -1.32 at 1796.42In the US a debt market, yields are lower but not helping the stock market:two year yield 4.225... 