Investment-grade bonds that pay a lower interest rate because of the issuing company's high credit rating. Angel bonds are the opposite of fallen angels, which are bonds that have been given a "junk" rating, and are therefore much more risky. 

|||An investment-grade bond is rated at minimum 'BBB' by S&P and Fitch, and 'Baa' by Moody's. If the company's ability to pay back the bond's principal is reduced, the bond rating may fall below investment-grade minimums and become a fallen angel.