Their specialists research a company's situation and identify a bond score for the business. Every rating service has its own formula for measuring threat and its own sort of score scale. Generally, ranking scales are spelled out in letter grades, where an AAA rating designates a safe, low-risk bond, and a D rating designates a high-risk bond.federal government bonds, are normally low-yield bonds. You can depend upon getting a payment however that payout will be small. what is a bond personal finance. On the other side of the spectrum, you have what's not-so-affectionately called, which are low-rated, high-risk bonds. In order to entice investors into buying these dangerous junk bonds, the releasing companies assure high yields.