The Trade Desk to join S&P 500, shares surge 15%
** Shares of The Trade Desk TTD.O surge 15% in extended trade, after the announcement that the software company will join the S&P 500 .SPX ** TTD will join the S&P 500, effective prior to the start of trading on Friday - S&P Dow Jones Indices ** TTD replaces Ansys ANSS.O, which is set to be acquired by Synopsys SNPS.O in an agreement expected to be completed on July 17 - S&P Dow Jones Indices (Reporting by Noel Randewich) ((noel.randewich@thomsonreuters.com))