In the world of finance, bonds are often classified based on their credit ratings. Those that fall below the Baa3 or BBB- rating are deemed non-investment grade. This is due to the potential for the issuer to default, making these bonds riskier but with the allure of higher yields. They are commonly referred to as speculative or high-yield bonds. It is important for investors to consider the level of risk they are willing to take on when considering these types of bonds.