The Bulge Bracket was a term used up until September 2008 to describe the largest investment banks (in terms of size and in terms of profitability). These were generally regarded to be Goldman Sachs, Morgan Stanley, JPMorgan, Citi, UBS, Credit Suisse, Merrill Lynch and Lehman Brothers.
The second half of 2008 saw an unprecedented shift in the definition of the Bulge Bracket, as Bank of America acquired Merrill Lynch, Lehman Brothers failed, and Morgan Stanley and Goldman Sachs converted themselves into traditional bank holding companies - see article.
These were all effects of the global Credit Crisis that was precipitated by Subprime mortgage failures.
