IPG Photonics Corp. /zigman2/quotes/203325788/composite IPGP -1.39% will join the S&P 500 index /zigman2/quotes/210599714/realtime SPX -1.11% replacing shares of Scripps Networks Interactive Inc. , according to S&P Dow Jones Indices late Friday. IPG, which makes lasers and laser equipment used in the materials industry, will replace Scripps before the market opens on March 7, S&P said. Scripps is being acquired by Discovery Communications Inc. . Shares of IPG were down 0.1% after hours.


