By Theodore Roosevelt V and Philip B. Duffy June 4, 2020 8:00 am ET Order Reprints Print Article Text size Photograph by Christopher Furlong/Getty Images The S&P 500 reached a record high on Feb. 19, crowning a decade-long bull market and the United States’ longest economic expansion. Over the next 22 trading days, the S&P fell more than 30%, faster than ever before. The speed of the fall revealed just how few market participants anticipated any immediate risk of a pandemic-induced recession.