Definition. 1  A blood clot is a thickened mass in the blood formed by tiny substances called platelets. Clots form to stop bleeding, such as at the site of cut. 2  As soon as a blood vessel wall is damagedâby a cut or similar traumaâa series of reactions normally takes place to activate platelets to stop the bleeding.
Series EE bonds mature after 30 years, meaning they can earn interest for that period of time. EE bonds are sold for half of face value and the U.S. Treasury Department guarantees they will reach face value after 20 years. Bonds must be owned for at least one year before redemption.
EE bonds purchased in the current period mature at twenty years and go into an automatic extension for ten years. These bonds accrue interest every month. If you bought a paper bond between May in 1997 and the end of April 2005, however, the interest rate varies according to a market based rate.