Nikkei Commodity Index is calculated using wholesale price of major materials which are sensitive for economic trend. As both "for 17 materials" and "for 42 materials" cover the materials of which actual goods are traded freely by many firms and of which prices fluctuate depending on demand and supply or competition, and as material coverage is reviewed in response to change in market size or trading condition, it maintains the reliability as index of leading economic indicators. At present, it is calculated using material coverage reviewed in October 2006. Index "for 17 materials" which is daily calculated has been released since November 1974, and index "for 42 materials" which is calculated monthly (and weekly as flash report) has been released since July 1975. As Nikkei Commodity Index tends to move in tandem with the economic recession or recovery, it has been utilized as an indicator for economic trends. In particular, "for 42 materials" is used as a factor in Indexes of Business Conditions (Leading Index) announced by Cabinet Office.