Platt's Metals Guide to Specifications
Price Indexes

Each of these three indexes is a straight arithmetic average calculated in such a way that its value would have been 100.00 on December 30, 1982. The prices averaged are usually from the next to last business day of the week. When the price is a range, the low end is used in calculating the average. MW Base Index includes Aluminum MW US Market, Copper MW Composite, Lead US Producer, Tin MW Composite, Zinc MW NA SHG, and Nickel Cathode NY Dealer. MW Precious Index includes Gold London Initial, Silver Comex 1st Position, Palladium MW NY Dealer and Platinum MW NY Dealer. MW Composite Index includes MW Base and MW Precious Indexes.