Exchange Traded Notes - ETN

What Does Exchange Traded Notes - ETN Mean?
A type of unsecured, unsubordinated debt security that was first issued by Barclays Bank PLC. This type of debt security differs from other types of bonds and notes because ETN returns are based upon the performance of a market index minus applicable fees, no period coupon payments are distributed and no principal protections exists.

Investopedia explains Exchange Traded Notes - ETN
The purpose of ETNs is to create a type of security that combines both the aspects of bonds and exchange traded funds (ETF). Similar to ETFs, ETNs are traded on a major exchange, such as the NYSE during normal trading hours. However, investors can also hold the debt security until maturity. At that time the issuer will give the investor a cash amount that would be equal to principal amount (subject to the day's index factor).

One factor that affects the ETN's value is the credit rating of the issuer. The value of the ETN may drop despite no change in the underlying index, instead due to a downgrade in the issuer's credit rating.