Reddit joins the S&P 500 on 18 August, replacing AvalonBay. Shares jumped 11%, though the stock is still down 31% so far this year.

Reddit (RDDT) stock jumped more than 12% in extended trading on Thursday after S&P Dow Jones Indices announced that the social media company...

Reddit shares have experienced a remarkable surge following the announcement of their inclusion in the S&P 500 index. With index funds compelled to acquire millions of Reddit…