Many factors help determine a certificate's collector value:
Certificates from the mining, energy and railroad industries are the most popular with collectors. Other industries or special collecting fields include banking, automobiles, aircraft, motion pictures, communications, tobacco, beverages and sports. Unissued certificates are usually worth one-fourth to one-eighth the value of issued ones (unless there are no issued ones that are in existence). Inexpensive issued common stocks and bonds dated between the 1960s and 1980s usually retail between $2 to $15 depending on availability. Those dating between the 1890s and 1930s usually sell for $20 to $60. Those over 100 years old retail from $25 to $100 or more, depending on quantity found. Autographed stocks normally sell anywhere between $100 to $10,000. Like anything else, the price is directly dependent upon supply and demand