Precious metal "precious" metal can also be determined by high demand or market value. Precious metals in bulk form are known as bullion and are traded on commodity markets. Bullion metals may be cast into ingots or minted into coins. The defining attribute of bullion is that it is valued by its mass and purity rather than by a face value as money. The level of purity varies from issue to issue. "Three nines" (99.9%) purity is common. The purest mass-produced bullion coins are in the Canadian Gold Maple Leaf series, which go up to 99.999% purity. A 100% pure bullion is
United States Commodity Funds United States Commodity Funds United States Commodity Funds LLC (USCF) is a US company based in Oakland, CA, specializing in managing exchange-traded commodity funds, which are often referred to as commodity-based exchange-traded funds (ETFs). USCF was one of the earliest issuers of exchange-traded commodity funds in the United States. It is best known for launching in 2006 the first crude oil based exchange traded commodity fund in the United States, United States Oil Fund, LP (ticker: USO), as well as launching in 2007 the first natural gas exchange traded commodity fund, United States Natural Gas Fund, LP (ticker: UNG). USO