<p>BB a long time ago used to mean Goldman Sachs, Morgan Stanley and Merrill Lynch – the three top monoline investment banks. Then it was adjusted to include Lehman Brothers and Bear Stearns. Then there was a financial crisis and BB was revised to mean basically the biggest banks still in existence, even if they are not pure investment banks. So Goldman Sachs, Morgan Stanley, Bank of America Merrill Lynch, JP Morgan Chase, Deutsche Bank, Credit Suisse and maybe a couple of others like UBS and Barclays.</p>
<p>Feel free to check wikipedia for bulge bracket information.</p>