U.S. stocks drifted lower in afternoon trading Friday, as the market headed for a lower close for the week. A slide in semiconductor stocks weighed on the Nasdaq composite index.

KEEPING SCORE: The Dow Jones industrial average slipped 30 points, or 0.2 percent, to 16,625 as of 3:12 p.m. Eastern time. The Standard & Poor’s 500 index fell nine points to 1,918. The Nasdaq composite lost 66 points, or 1.5 percent, to 4,311.