The rating agencies weren't cutting the ratings as they should and these European banks were just kind of naively trusting and it just didn't get figured out.

信用评级机构并未按照实际评级,这些欧洲银行却很傻很天真地相信了,没有认识到潜在的风险

耶鲁公开课 - 金融市场课程节选