|The old moto "E Pluribus Unum" was printed on the back of the U.S. penny.|
When Congress bailed out insolvent Wall Street banks in 2008, not only did this move enable Wall Street to continue paying large bonuses, it gave America's largest banks the resources to swallow even more small banks. The appearance of four humongous banks marked the culmination of a process that had been going on for two decades.
Somehow the Big Four escaped bankruptcy and were declared to have passed Treasury Secretary Tim Geithner's "stress test" in 2009. To mark the occasion, "E Pluribus Quattuor" was proposed as the new moto for the United States America by a committee of the U.S. Senate.
E Pluribus Quattuor describes an action: Many uniting into four. An accurate translation of the motto is "Out of many, four."
Too big to fail chart h/t James Fallows