 Shares of DuPont de Nemours Inc. DD, -1.68 dropped 1.7 in premarket trading Tuesday, after the specialty materials and chemicals company reported second-quarter profit and sales that beat expectations but provided a downbeat third-quarter outlook, citing foreign currency headwinds and unplanned downtime at a Virginia site. Second-quarter net income rose to 787 million, or 1.55 a share, including 85 cents a share from discontinued operations, from 478 million, or 90 cents a share, in the year-ago period. 