Banks are historically the single most critical aspect of commercial real estate lending because they are the largest portion. Being private, though, the data is largely unavailable for examination. It's why a category like CMBS gains attention beyond its natural importance because there is a greater amount of public data.

However, there are some views into commercial banks. Trepp just released an analysis of bank criticized CRE loans. The database is "a consortium of CRE loan data from participating US banks … where we also track CRE loan performance metrics by geography and property type."

The data includes criticized loans for which a bank has heightened concerns, although the loans may not be delinquent. "Trepp takes banks' internal risk ratings for their loans and standardizes them to a scale of 1–9, ranked by increasing risk for loan loss and default, and loans with a risk rating of 6 or higher are classified as criticized loans."