Culminating weeks of increasingly angry words and bolder action aimed at Wall Street, President Barack Obama has proposed the toughest new restrictions yet on the nation's largest banks in the aftermath of the nation's financial crisis.

The plan would reconstruct a barrier similar to one erected during the Great Depression, but repealed in 1999, to limit the risks that banks could take with federally insured deposits. Obama also wants to broaden restrictions on the growth of large banks so none would have too large a share of the U.S. financial system.

It's unclear if the proposal will get Congressional approval, but its unveiling Thursday helped shove down the Dow Jones index of 30 blue-chip stocks 213 points, or 2 percent, the biggest decline since last fall.

With Obama railing about Wall Street's "huge, reckless risks in pursuit of quick profits and massive bonuses," shares of JPMorgan Chase & Co., Bank of America Corp., Goldman Sachs Group Inc. and Citigroup Inc. each lost at least 4 percent.

Obama is proposing a revised version of the Glass-Steagall restrictions enacted after the market crash that triggered the Great Depression. That law separated commercial banks and investment banks.

Commercial banks still would be allowed to own investment banks, but they would have to adhere to new limitations designed to reduce the risk to depositors.

Banks with federally insured deposits would be prohibited from owning or investing in hedge or private equity funds. They would not be able to use funds to trade on their own behalf. They would still be able to trade securities on a customer's behalf.