<P> On September 20, the London Stock Exchange crashed when top British investor Clarence Hatry and many of his associates were jailed for fraud and forgery . The London crash greatly weakened the optimism of American investment in markets overseas . In the days leading up to the crash, the market was severely unstable . Periods of selling and high volumes were interspersed with brief periods of rising prices and recovery . </P> <P> Selling intensified in mid-October . On October 24 ("Black Thursday"), the market lost 11 percent of its value at the opening bell on very heavy trading . The huge volume meant that the report of prices on the ticker tape in brokerage offices around the nation was hours late, so investors had no idea what most stocks were actually trading for at that moment, increasing panic . Several leading Wall Street bankers met to find a solution to the panic and chaos on the trading floor . The meeting included Thomas W. Lamont, acting head of Morgan Bank; Albert Wiggin, head of the Chase National Bank; and Charles E. Mitchell, president of the National City Bank of New York . They chose Richard Whitney, vice president of the Exchange, to act on their behalf . </P> <P> With the bankers' financial resources behind him, Whitney placed a bid to purchase a large block of shares in U.S. Steel at a price well above the current market . As traders watched, Whitney then placed similar bids on other "blue chip" stocks . This tactic was similar to one that had ended the Panic of 1907 . It succeeded in halting the slide . The Dow Jones Industrial Average recovered, closing with it down only 6.38 points for the day . The rally continued on Friday, October 25, and the half day session on Saturday the 26th but, unlike 1907, the respite was only temporary . </P> <P> Over the weekend, the events were covered by the newspapers across the United States . On October 28, "Black Monday", more investors facing margin calls decided to get out of the market, and the slide continued with a record loss in the Dow for the day of 38.33 points, or 13% . </P>

Who was involved in the wall street crash