Two years after President Barack Obama vowed to eliminate the danger of financial institutions that are too big to fail, the nation’s largest banks are bigger than they were before the financial meltdown. Five banks—JPMorgan Chase (JPM), Bank of America (BAC), Citigroup (C), Wells Fargo (WFC), and Goldman Sachs (GS)—held more than $8.5 trillion in assets at the end of 2011, equal to 56 percent of the U.S. economy, according to the Federal Reserve. That’s up from 43 percent five years earlier.