As the anniversary of 1987 "Black Monday" approaches on October 19, Wall Street remembers one of the most catastrophic events that shook the global financial system. The Dow Jones Industrial Average plunged by almost 23%（508 points）, and the S&P 500 also plummeted more than 20% in a daylong selling frenzy that spread worldwide. It severely tested the limits of the financial system on that day.
As the ominous d...