Stock futures drifted lower during the early session, leading to a lower open for the broader market. Weighing on the market in the early going is Apple (AAPL), which is down more than 4% in early trading after supplier Lumentum Holdings (LITE) cut its outlook. While Lumentum did not call out Apple by name, its request from one of its "largest Industrial and Consumer customers for laser diodes for 3D sensing" to "materially reduce shipments" is widely believed to be referring to the iPhone maker. About 45 minutes into the session, the S&P is down 25 points, the Dow is down 230 points and the Nasdaq is down 124 points.