 Shares of Lumentum Holdings Inc. LITE, 2.04 slumped 8.5 in premarket trading Tuesday, after the optical networking products company reported fiscal fourth-quarter earnings that beat expectations but provided a downbeat profit outlook for the current quarter. Net income for the quarter to July 2 rose to 34.7 million, or 49 cents a share, from 21.5 million, or 28 cents a share, in the year-ago period. 