Note that the “highest rates” quoted here are the highest rates available nationwide that Investopedia has identified in its daily rate searches of hundreds of banks and credit unions. This is very different from the national average, which includes all banks offering a CD with this term, including many large banks that pay paltry interest. Thus, the national averages are always quite low, while the highest rates you can find while shopping are often five, 10, or even 15 times higher.