The dollar is a widely recognized and influential currency used as a medium of exchange in many countries around the world. Here are some reasons why the dollar has become known as the "king of currency":

Global Reserve Currency: The U.S. dollar is the most widely held reserve currency globally. Many central banks and governments hold significant amounts of U.S. dollars as part of their foreign exchange reserves. This status provides stability and trust in the currency's value.

Economic and Political Power: The United States has the world's largest economy and a strong political influence globally. This economic and political power contributes to the perception of the dollar as a reliable and trustworthy currency.

International Trade: The dollar is commonly used in international trade, serving as a preferred currency for conducting business transactions worldwide. Many commodities, such as oil, are priced and traded in dollars, further strengthening its dominance.

Financial Markets: The U.S. financial markets, particularly the New York Stock Exchange and Wall Street, play a crucial role in the global economy. The dollar's prominence in these markets enhances its standing as a primary currency for investments and financial activities.

Stable and Liquid: The U.S. dollar is considered relatively stable compared to other currencies, which makes it attractive for investors and traders. Its liquidity, meaning it can be easily bought or sold, further solidifies its status as a dominant currency.

Confidence and Trust: The dollar's longstanding history as a reliable currency, backed by the strength of the U.S. economy, has created confidence and trust among market participants. This trust is crucial for a currency to be widely accepted and used.

It is important to note that while the U.S. dollar holds significant influence, other currencies such as the euro, yen, and pound sterling also play important roles in the global economy. The "king of currency" reference primarily reflects the dollar's dominant position rather than implying absolute supremacy over other currencies.