Ansys (ANSS) witnessed a jump in share price last session on above-average trading volume. The latest trend in earnings estimate revisions for the stock doesn't suggest further strength down the road.

The Trade Desk shares are up 14% in premarket trading Tuesday, a day after S&P Dow Jones Indices said the digital advertising company will be replacing software maker Ansys in the S&P 500 Index.

TTD stock rose after being added to S&P 500, receiving positive ratings from analysts. Price forecast lowered but still bullish on long-term growth.

Trade Desk’s stock is soaring, with the ad-tech company set to replace Ansys in the benchmark index later this week.

Shares of Trade Desk Inc (NASDAQ:TTD) are up 11.4% to trade at $84.06 this morning, after news broke that the software firm will replace Ansys (ANSS) on the S&P 500 Index (SPX) before the open this Friday, July 18. The change comes after Synopsys (SNPS) agreed to purchase Ansys for $35 billion by the end of this week.

China’s top antitrust regulator has conditionally approved the $35B acquisition of Ansys by Synopsys. The approval by the State Administration for Market Regulation (SAMR) was confirmed on Monday, just days after the United States quietly relaxed recent export restrictions on chip design software.

The merged ANSYS and Synopsys companies will be one of the most important players in the future of AI. Click here to find out why ANSS is a Buy.

Stocks often rally when they're added to a major index, as fund managers need to rebalance their portfolios to reflect the changes. With a market cap of $37 billion, the company falls right about in the middle of the S&P 500 by valuation.

Trade Desk (TTD) stock is surging on news that the company will join the S&P 500 (^GSPC), replacing Ansys (ANSS). Robinhood (HOOD) and Applovin (APP) are trading slightly lower after not making the cut to join the index once again.