I don't think this "annually" is correct. I thought they did it quarterly. This seems to agree:However, here is an important point: per the S&P 500 methodology, "the index is reconstituted annually, after the close of the third Friday in June, using a reference date of the last business day of May". I believe this means that if Tesla does not qualify for the S&P 500 with Q1 2020 earnings, they will need to wait until 2021 as the "last business day in May" does not afford the benefit of Q2 results.
From: | S&P 500 Historical Components & Changes
During 2017, S&P Dow Jones Indices replaced 27 companies. This is two more than in 2016 when 29 stocks were shuffled.
During the first quarter of 2017, Advanced Micro Devices Inc (AMD), Raymond James Financial (RJF), Alexandria Real Estate Equities (ARE), Synopsys Inc (SNPS), Dish Network (DISH), Regency Centers Corp (REG), CBOE Holdings Inc (CBOE), Incyte Corp (INCY) and IDEXX Laboratories (IDXX) were added to the index. Urban Outfitters (URBN), Frontier Communications (FTR), First Solar Inc (FSLR), Harman Int’l Industries (HAR), Linear Technology Corp. (LLTC), Endo International plc (ENDP), Pitney Bowes Inc (PBI), Spectra Energy Corp (SE) and St. Jude Medical Inc (STJ) were removed.
During the second quarter, Everest Re Group (RE), Hilton Worldwide Holdings Inc. (HLT), Align Technology Inc. (ALGN), ANSYS Inc. (ANSS), IHS Markit Ltd. (INFO), Gartner Inc (IT) and DXC Technology (DXC) replaced Mead Johnson (MJN), Yahoo! Inc. (YHOO), Teradata Corp. (TDC), Ryder Systems Inc. (R), Tegna, Inc. (TGNA), Dun & Bradstreet (DNB) and Southwestern Energy (SWN).
During the thirth quarter, Cadence Design Systems (CDNS), SBA Communications (SBAC), IQVIA Holdings Inc (IQV), Brighthouse Financial Inc (BHF), MGM Resorts Int’l (MGM), ResMed Inc. (RMD), Packaging Corporation of America (PKG), A.O. Smith (AOS) and Duke Realty Corp (DRE) were added and Staples Inc. (SPLS), DuPont (DD), Whole Foods Market (WFM), AutoNation Inc (AN), Reynolds American Inc. (RAI), Mallinckrodt (MNK), Murphy Oil (MUR), Bed Bath & Beyond (BBBY) and Transocean (RIG) were removed.
During the last quarter of the year, Huntington Ingalls Industries Inc. (HII) and Norwegian Cruise Line Holdings (NCLH) replaced C. R. Bard Inc. (BCR) and Level 3 Communications (LVLT).