The Dow fell more than 600 points Monday after a one-two punch: the first-ever Standard & Poor's downgrade of U.S. debt, then the downgrading of government-backed mortgage debt. The Dow's one-day drop was its biggest point loss in a single day since Dec. 1, 2008, and its sixth biggest point drop in its history.
The Dow closed down 634 points, the S&P 500 lost 79 points and the Nasdaq ended 174 points lower, dropping almost 7 percent.
Obama spoke Monday afternoon, saying the United States knew well before the S&P downgrade that it had a debt problem. "The U.S. will always be a triple-A country, despite what rating agencies say," he said.
The good news, Obama said, is the debt is a "solvable" problem that can be addressed through tax reform and spending cuts.
Investors didn't seem as optimistic: The Dow plunged an additional 100 points to hover around 500 after the speech.
Monday saw about $2.3 trillion in U.S. investor wealth wiped out.