The highest tranche of an asset backed security or other structured financial product. An A-note is senior to other notes, such as B-notes in bankruptcy or other credit proceedings, and is paid back first with funds from the underlying assets. They can be labeled AAA, AA, or A, depending on the credit quality of the underlying asset. Can also be referred to as a class a note.
Lower tranches of notes are referred to as subordinate notes. While an A-note does offer more credit protection than other notes, investors in this tranche must still pay attention to the credit worthiness of investments in the subordinate classes. If the risk levels of those investments increase, the chances of default and repayment risk rise.