The price of gold (XAU) has received widespread attention around the world. Gold was the foundation of capitalist economies for hundreds of years before the gold standard was abolished. After World War II, the United States established the "Bretton Woods monetary system", in which the U.S. dollar was pegged to gold, and the currencies of various countries were pegged to the U.S. dollar. The U.S. dollar became the "world currency" and was known as the "U.S. dollar." In the 1970s, the United States was mired in the Vietnam War and fiscal deficits. The depreciation of the U.S. dollar prompted European countries to give up their peg to the U.S. dollar, and the price of gold began to float freely, thus giving birth to spot gold, or "London gold." The "September 11" incident in the United States in 2001 made gold's safe-haven function recognized by the world and became an effective asset against inflation, thus starting a ten-year bull market for gold. Fluctuations in gold prices are more affected by geopolitical situations and are usually inversely proportional to fluctuations in the U.S. dollar and stock markets. The chemical symbol of gold in the periodic table of elements is AU, and X represents that it does not belong to any country, and the unit is ounces/dollars.