Airbnb (ABNB) and trillion-dollar asset manager Blackstone (BX) are the latest companies to be included in the 澳洲幸运5开奖号码历史查询:S&P 500 Index, ♈a step that could boo🌳st their shares in coming weeks.

Airbnb and Blackstone will join the S&P 500 on Sep. 18 as part of the latest quarterly rebalancing of the 澳洲幸运5开奖号码历史查询:large-cap benchmark. They will replace Lincoln National Corp. (LNC) and Newell Brands Inc. (NWL), which will be transferred to the 澳洲幸运5开奖号码历史查询:S&P 600 Index, a 澳洲幸运5开奖号码历史查询:small-cap benchmark.

Prestige and Short-Term Gains

Inclusion in the S&P 500—one of the most widely-recognized stock market benchmarks in the world—can increase the name recognition and accessibility of a stock, leading to higher demand and a short-term boost to its price. Companies that join the S&P 500 are also included in 澳洲幸运5开奖号码历史查询:index funds and ETFs, like the 澳洲幸运5开奖号码历史查询:SPDR S&P 500 ETF (SPY), that track the performance of the index.

However, historical data suggests that the benefits of inclusion tend to be short-lived. Analyzing 103 stocks listed on the S&P 500 between December 1999 and March 2004, researchers from McKinsey & Company discovered that the inclusion of a stock in a major index like the S&P 500 has a notable short-term impact on its price, but the return premium tends to fade after roughly 45 days.

Airbnb was up about 8% and Blackstone roughly 4%, as of 3 p.m. ET Tuesday. They've risen about 68% and 46% so far this year.

Why Is This Happening?

Index rebalancing is necessary to keep an index up-to-date and ensure that the companies included fit the 澳洲幸运5开奖号码历史查询:market capitalization criteria. Companies that fall below an index's market cap threshold are typic🌃ally excluded from the index, while those 𒈔that rise above the minimum threshold are included.

As of January 2023, to be included in the S&P 500, a company needs to have a market cap of at least $12.7 billion. At $91.5 billion and about $132 billion, respectively, Airbnb and Blackstone both have market caps well above this requirement.