Aug 30 (Reuters) - U.S. stocks opened lower on Thursday, halting a four-day record run for the S&P 500 and the Nasdaq indexes, as optimism over U.S.-Canada trade talks was overshadowed by concerns over Washington's tariff dispute with China.
The Dow Jones Industrial Average fell 25.56 points, or 0.10 percent, at the open to 26,099.01. The S&P 500 opened lower by 5.10 points, or 0.18 percent, at 2,908.94. The Nasdaq Composite dropped 15.49 points, or 0.19 percent, to 8,094.20 at the opening bell. (Reporting by Sruthi Shankar in Bengaluru; Editing by Shounak Dasgupta)