Commodity money as a theoretical backing for federally issued "gold certificates" to substitute for the gold. Between 1933 and 1970 (when the U.S. officially left the gold standard), one U.S. dollar was technically worth exactly 1/35 of a troy ounce (889 mg) of gold. However, actual trade in gold bullion as a precious metal within the United States was banned after 1933, with the explicit purpose of preventing the "hoarding" of private gold during an economic depression period in which maximal circulation of money was desired by influential economists. This was a fairly typical transition from commodity to representative to fiat money,
Commodity index fund Commodity index fund A commodity index fund is a fund whose assets are invested in financial instruments based on or linked to a commodity price index. In just about every case the index is in fact a commodity futures index. You cannot invest in an index, but you can invest in a fund. A Commodity Index Fund is a fund which either buys and sells futures to replicate the performance of the index, or sometimes enters into swaps with investment banks who themselves then trade the futures. The biggest and best known such fund is the Pimco Real Return Strategy