The S&P 500 and Nasdaq notched their eighth week of gains in the last nine, but momentum ran out on Friday as shares ended the day lower after a thinly traded session.

The Dow Jones industrial average <.DJI> dropped 2.73 points, or 0.02 percent, to end unofficially at 12,977.57. The Standard & Poor's 500 Index <.SPX> shed 4.46 points, or 0.32 percent, to finish unofficially at 1,369.63. The Nasdaq Composite Index <.IXIC> fell 12.78 points, or 0.43 percent, to close unofficially at 2,976.19.

For the week, the S&P 500 advanced 0.3 percent and the Nasdaq gained 0.4 percent.

But the Dow ended the week just a touch lower - down 0.05 percent.

(Reporting by Edward Krudy; Editing by Jan Paschal)

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