Carvana (CVNA) jumped almost 10% in after-hours trading Friday after S&P Dow Jones Indices announced the company will be added to the S&P 500 — one of the most influential stock market benchmarks in the world. The move marks a major milestone for the used-car retailer, which has staged a dramatic turnaround over the last two years.

S&P said Carvana will officially join the S&P 500 before the market opens on December 22. The announcement triggered immediate buying pressure as index funds and institutional investors must now add CVNA to their portfolios, increasing demand for the stock.

Carvana’s Class A shares were last up +9.9% after hours.

Two additional companies — CRH (CRH) and Comfort Systems USA (FIX) — will also be added to the index. CRH jumped 7%, and FIX rose 1.9% in after-hours trading following the news.

To make room for the new additions, S&P will remove three companies from the index:

· LKQ (LKQ)

· Solstice Advanced Materials (SOLS)

· Mohawk Industries (MHK)

Being added to the S&P 500 is widely viewed as a vote of confidence in a company’s stability, scale, and liquidity — and often results in a near-term stock price boost due to mandatory index-fund demand.