091508trader.jpgThe Dow Jones industrial average lost over 500 points today, the biggest one-day decline for the Dow since Sept. 17, 2001, when the market reopened for trading after the 9/11 terrorist attacks. "You have to throw out the history books because there's really nothing to compare this to," Jim Dunigan, chief investment officer at PNC Advisors, tells CNN. Stephen Leeb, president at Leeb Capital Management, says, "People are panicked but it's not the end of capitalism. This may usher in something worse than what we've seen in terms of the economy, but the companies left standing at the end of this will be OK." Phew! The last half hour of trading saw heavy selling despite Governor Paterson's effort to calm investors by letting faltering insurance company A.I.G. borrow $20 billion from its subsidiaries. And a group of 10 banks have given up to $7 billion each to create a $70 billion lending pool to help smaller institutions.