Diana Henriques: Lessons Not Learned On Black Monday, 1987

For decades on Wall Street, “Black Monday” has meant October 19, 1987. Despite the many difficult days since then — the 1998 currency panic, the 2001 terrorist attacks, the 2008 crisis — Black Monday still stands as the worst day in American stock market history. No other crash, not even the historic plunge of 1929, comes close. Black Monday was evidence that a new and frightening era had arrived on Wall Street – one in which computer power, human ingenuity and herd instincts all combined to form a juggernaut that is rumbling unpredictably through the markets to this day. Q1…