Reddit added to S&P 500

S&P Dow Jones Indices announced on August 14, 2026 that Reddit would join the S&P 500 index, replacing AvalonBay Communities. The change is effective before markets open on August 18. Analysts at JPMorgan Chase estimate index funds tracking the S&P 500 could need to buy 16.7 million Reddit shares, nearly three times the stock's average daily trading volume of about 5.98 million shares since its IPO in March 2024. Reddit shares jumped more than 12% in premarket trading following the announcement. The stock had fallen more than 31% year-to-date through Thursday's close and is down more than 42% from its all-time high reached in September 2025. AvalonBay is being removed after agreeing in May to an all-stock merger with Equity Residential to form a rental housing company with an enterprise value of $69 billion. The combined company, to be called Vivmark Residential, will remain in the S&P 500 after the merger is completed. Stephens analyst Melissa Roberts noted that new S&P 500 additions have historically outperformed the benchmark from announcement to inclusion, but typically give back some gains and lag the benchmark over the next three months by about 2%.