Production of proof American Silver Eagles has been consistent since 1986, with the lone glaring exception of 2009, when a shortage of silver blanks amidst soaring demand for bullion led to a forced hiatus of proof silver eagles. Many proof variants have been struck since 2006, when the first reverse proof was struck and proved quite popular with collectors. Other reverse proofs issued since have also enjoyed great demand, and all reverse proof American Silver Eagles trade for many times over spot value.