"How the Giants of Finance Shrunk, Then Grew, Under the Financial Crisis" [nytimes.com] displays the market capitalization of 29 of the biggest financial firms on September 11, 2009.
The "animated treemap" graph demonstrates the overall and relative changes in market capitalization over time, since the stock market's peak in October 2007. Since then, Wall Street's landscape has been permanently altered, as financial giants crumbled under the weight of the financial crisis. While most firms are still considerably smaller, 2 banks (i.e. JPMorgan Chase and Well Fargo) are actually slightly larger than they were at the market's peak.