Credit Rating
An assessment of a borrower's creditworthiness by rating agencies.
In depth
Major agencies: S&P, Moody's, Fitch. Investment grade: BBB-/Baa3 and above. High yield ("junk"): below BBB-/Baa3. Ratings affect borrowing costs significantly — a downgrade from investment grade to junk forces selling by funds restricted to IG, often spiking yields.