
Shares of ad-tech firm Trade Desk TTD.O jump 13.9% to $85.9 premarket
Stock on track to open at highest level in over five months, if gains hold
TTD will replace engineering design firm Ansys ANSS.O in the S&P 500 .SPX, effective before markets open on Friday, July 18
China's market regulator on Monday conditionally approved U.S. chip design software provider Synopsys' SNPS.O acquisition of ANSS
Synopsys said on Monday that the companies now expect to close the transaction on or around July 17
Stephens analyst Melissa Roberts estimates passive funds that track the S&P 500 will need to buy nearly 76 mln TTD shares, implying about nine days of buying demand
As of Monday's close, TTD down more than 35% YTD, compared with a 8.7% rise in the Nasdaq 100 .NDX index