Their specialists research a business's circumstance and figure out a bond score for the business. Every ranking service has its own formula for measuring danger and its own kind of score scale. Typically, ranking scales are spelled out in letter grades, where an AAA rating designates a safe, low-risk bond, and a D ranking designates a high-risk bond.government bonds, are typically low-yield bonds. You can depend on getting a payment but that payment will be small. what is a bond finance rt511. On the other side of the spectrum, you have what's not-so-affectionately known as, which are low-rated, high-risk bonds. In order to lure financiers into buying these risky junk bonds, the issuing business guarantee high yields.