I'm aware of all of those issues. The point is a company being "unrated" is usually a synonym in the credit world for being below CCC. Typically a company in trouble gets to the CCC rank, and at some point the credit companies will simply stop rating them. There are exceptions, but I take the fact that 20% of VVR's investments are unrated to mean they have a lot of junk-bond-quality corporate loans they are supporting.