<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 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> <P> The next day, "Black Tuesday", October 29, 1929, about 16 million shares traded as the panic selling reached its peak . Some stocks actually had no buyers at any price that day ("air pockets"). The Dow lost an additional 30 points, or 12 percent . The volume of stocks traded on October 29, 1929, was a record that was not broken for nearly 40 years . </P> <P> On October 29, William C. Durant joined with members of the Rockefeller family and other financial giants to buy large quantities of stocks to demonstrate to the public their confidence in the market, but their efforts failed to stop the large decline in prices . Due to the massive volume of stocks traded that day, the ticker did not stop running until about 7: 45 p.m. The market had lost over $30 billion in the space of two days which included $14 billion on October 29 alone . </P>

What caused the new york stock exchange to crash in 1929