Vanguard Extended Duration Treasury ETF(AMEX:EDV)

The fund is passively managed to hold a portfolio of 20- to 30-year Treasury STRIPS, which represents a single coupon or principal payment on a US Treasury security that has been stripped into separately tradable components. These securities promise a single payment upon maturity in the next 20-30 years without any interim coupon payments. The fund has a massively long effective duration because zero-coupon bonds carry significantly more interest rate risk than their coupon-bearing counterparts. The fund's holdings are selected through a sampling process in which at least 80% of the funds' assets are normally invested in US Treasury securities held by the index.