State Street Bank and Trust Company v. Signature Financial Group, Inc., 149 F.3d 1368 (Fed. Cir. 1998), also referred to as State Street or State Street Bank, was a 1998 decision of the United States Court of Appeals for the Federal Circuit concerning the patentability of business methods. "State Street" for a time established the principle that a claimed invention was eligible for protection by a patent in the United States if it involved some practical application and, in the words of the "State Street" opinion, "it produces a useful, concrete and tangible result."