Exchange-traded notes (ETNs) are unsecured debt securities issued by financial institutions. They are designed to track the performance of a specific index or benchmark, such as commodities or currencies, and are traded on stock exchanges like NASDAQ or NYSE. Unlike traditional bonds, ETNs do not pay periodic interest; instead, they provide a return based on the performance of the underlying asset. Investors can buy and sell ETNs throughout the trading day, similar to stocks. However, ETNs carry credit risk, meaning if the issuing bank defaults, investors may lose their principal. They also have tax implications, as gains may be taxed as ordinary income rather than capital gains.