Я не знаю, как это интерпретировать.

[cass1an]

"We examine the payoff performance, up to the end of 2013, of non-agency residential mortgage-backed securities (RMBS), issued up to 2008. <...> Second, AAA securities did ok: on average, their total cumulated losses up to 2013 are 2.3 percent. Third, the subprime AAA-rated segment did particularly well.  <...> Together, these facts provide challenge the conventional narrative, that improper ratings of RMBS were a major factor in the financial crisis of 2008."
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3159552