Out of the Gate: AK Steel up, added to S&P 500

Standard & Poor's announced late Thursday that the West Chester, Ohio, steel maker was being added to its large-cap S&P 500 index. Shares of companies added to the index usually receive a bump as funds that track the index buy the shares.

AK Steel shares rose $4.49, or 7.1 percent, to $67.67 in early trading. Shares are up about 39 percent for the first half of this year and more than 70 percent over the past 52 weeks as the steel industry benefits from higher demand and prices.