416 points (3.3%)
The 778-point drop on Sept. 29, 2008 was Dow Jones Industrial Average's biggest single-day point drop ever. But there have been other ugly days in the index's history. On Feb. 27, 2007, slumping Chinese stocks, fears over the domestic market's steadiness and
what appeared to be a Taliban assassination attempt on Vice President Dick Cheney during his visit to Afghanistan sent the market into its biggest tailspin since it reopened after the Sept. 11, 2001 terrorist attacks.