LONDON, ENGLAND - MARCH 13: A Sotheby's employee holds an American 1794 silver dollar, estimated to be worth between 3 and 5 million United States dollars, at Sotheby's auction house on March 13, 2015 in London, England. A collection of over 600 coins will be sold at a series of auctions at Sotheby's New York beginning in May, which is estimated to sell for a total exceeding 100 million US dollars. (Photo by Rob Stothard/Getty Images)
