Speaking to a business audience in Birmingham, the president said America's economy is "fundamentally sound."
He cited strong first-quarter growth, low inflation and rising productivity as reasons American investors should be confident.
As Bush spoke at the University of Alabama Birmingham campus, the Dow Jones Industrial Average was down nearly 300 points. That's on top of last week's drop of nearly 700 points.
A key factor in the sell-off has been the accounting scandals that have rocked major companies.
Bush renewed his pledge to hold accountable those behind the scandals.