The companies will replace American Airlines Group Inc., Etsy Inc. and Bio-Rad Laboratories Inc., according to a press release from S&P Dow Jones Indices Friday. The changes are set to go into effect prior to the open of trading on Sept. 23. 

The additions of Palantir and Dell reflect how technology companies, and artificial intelligence-related names in particular, are reshaping the market. Palantir, the data-analysis software company co-founded by billionaire tech investor Peter Thiel, has grown from serving the US intelligence community to working with dozens of government agencies, and more recently expanding its commercial business. 

Shares of the Denver-based company have risen over 75% this year as investors bet the software and surveillance firm will benefit from growing demand for its AI tools. Shares jumped as much as 8.4% in after-hours trading Friday. 

Dell, the Round Rock, Texas-based company best know for personal computers and monitors, reported better-than-expected revenue last week as a result of an increase in sales of servers built for handling AI workloads.

Shares of the hardware giant jumped as much as 8.7% after the bell, while insurance company Erie Indemnity rose as much as 5.5%.

Companies must have a market capitalization of at least $18 billion and meet profitability, liquidity and share-float standards to qualify for the S&P 500, per August’s methodology.

Meanwhile, the removal of American Airlines from the US equity benchmark underscores the challenges the industry has faced of late, including delayed deliveries of planes and rising labor costs. The air carrier slashed its profit outlook in July after expectations for domestic demand proved too rosy. Its shares dropped 0.8% Friday post-market, adding to a 21% year-to-date decline. 

Inclusion in the US equity benchmark can elevate a company’s profile and is becoming more important as passive investment funds grow. Expulsion from the benchmark can weigh on stock prices, as index funds sell shares to realign with the S&P 500’s new composition.

(Updates with additional details throughout)