The U.S. dollar's role as the core currency in the forex market stems from its dominance as the global reserve currency. Since World War II, the dollar gradually became the world's reserve currency through its link to gold. Although the U.S. left the gold standard in 1971, the dollar has remained the primary currency in global foreign exchange reserves, playing a significant role in international transactions and investments. According to data from the International Monetary Fund (IMF), the dollar currently makes up more than 60% of global foreign exchange reserves and serves as the standard currency for global settlement, particularly in commodity transactions such as oil and gold. Moreover, the size of the U.S. economy and the depth and liquidity of its financial markets have helped maintain the dollar's dominant position in the global forex market. The global influence of the U.S. economy and its innovation capabilities have made the dollar irreplaceable in global trade. Additionally, U.S. financial markets, including its bond, stock, and foreign exchange markets, attract global investors due to their high liquidity and scale, further driving the widespread use of the dollar. The Federal Reserve's monetary policy also has a significant impact on global markets, especially in areas like interest rates, capital flows, and financial market stability. Therefore, the dollar's central role in the global payment system makes it the foundation of the forex market.