In the U.S. part of the Global Financial Crisis now 17 years back, credit rating agencies were one of the painful industry segments. Many properties and securitization deals were offered undeserved pumped-up ratings that convinced investors to pour money into poor investments.

But a recent debacle on AAA bonds from a CMBS deal has raised the specter of how trustworthy some ratings might be.

CRED iQ recently wrote about 1740 Broadway, "Special servicing workout fees, servicer advances, and other expenses totaled $62.3 million, which left only $117.2 million of net proceeds available to the Class-A investors, which had an unpaid principal balance of $157.5 million. This resulted in a $40.3 million loss (25.6% loss severity) to the A tranche and wiped out all subordinate tranches."