Stocks opened slightly lower Friday as investors looked to wrap up a volatile week. The Dow Jones Industrial Average /zigman2/quotes/210598065/realtime DJIA +0.21% was off 36 points, or 0.1%, at 34,731, while the S&P 500 /zigman2/quotes/210599714/realtime SPX -0.11% edged down 0.2% to 4,440. The Nasdaq Composite /zigman2/quotes/210598365/realtime COMP -0.82% fell 0.5% to 14,977. Stocks had enjoyed a sharp two-day rebound that put major indexes back in the green for the week on Thursday. Friday's losses left the Dow up 0.5% for the week, while the S&P 500 was clinging to a 0.2% gain and the Nasdaq was down 0.5%.