The crisis "is nothing less than the final verdict on an economic philosophy that has completely failed", he told supporters.
"Senator McCain's approach was the same as the Bush administration's: support ideological policies that made the crisis more likely; do nothing as the crisis hits; and then scramble as the whole thing collapses."
Obama's "21st century regulatory framework" would require mortgage brokers and investment houses to submit to the same regulatory supervision as commercial banks.
Both presidential candidates are trying to use the latest financial crisis to help benefit their campaigns ahead of the election on November 4.
In a speech in Florida, McCain denounced the "recklessness of Wall Street".
"People have a right to know when their jobs, pensions, investments, and our whole economy are being put at risk by the recklessness of Wall Street," he said.
"I can assure you that if I am president, we're not going to tolerate that anymore. In my administration, we're going to hold people on Wall Street responsible," McCain said.
A new Obama advertisement repeatedly showed McCain's remark in Florida on Monday that the economy was fundamentally "strong" superimposed with news-style captions detailing current economic woes.
Obama also condemned McCain's ownership of seven homes.
"If you own seven homes, the judge is free to write down any or all of the debt on your second, third, fourth, fifth, sixth or seventh homes," Obama said in Colorado.
"Now that may be of comfort to Senator McCain, but that's the kind of out-of-touch Washington loophole that makes no sense."
But Tucker Bounds, McCain's spokesman, attacked Obama's recipe for recovery.
"Barack Obama offered nothing new except for sharp criticisms of the most fundamental elements of the American economy and pessimism about genuine efforts to restore our country's prosperity," he said.