A business development company is a US closed-end fund created to lend to smaller private companies, and required to disclose its holdings publicly, position by position.
What it looks like in a filing
The disclosure obligation is the whole point here. A private credit fund outside this regime publishes nothing at the loan level; a BDC publishes every position it holds, every quarter, with the fair value it assigns.
What Kanonstone measures with it
The panel covers 170 vehicles and 101 manager groups. It is a window onto private credit, not the whole of it — the loans measured are those held by at least one reporting vehicle.