Materials stocks were trading higher on Wednesday as the best performing of the 10 major S&P sectors heading into the midpoint of the session, led by gains in DuPont and Nucor Corp. DuPont shares were moving up 4.4 percent at $68.75 after activist investor Nelson Peltz's Trian Fund Management, among the biggest shareholders in the company, urged it to separate its high-growth businesses from those with strong cash flows. Nucor shares were 3.8 percent higher at $57.75 after the steelmaker forecast third-quarter earnings between 70 to 75 cents a share, well above the current Thomson Reuters estimate of 61 cents a share.