Currencies are the monetary units that nations use to conduct trade, settle debts, and store value. Every economy in the world runs on its currency and the exchange rate between any two currencies reflects the relative strength of their economies, their interest rates, their inflation, and the confidence the world has in their institutions.
The modern currency system dates back to 1944 when the Bretton Woods Agreement pegged major currencies to the US dollar, which was itself convertible to gold. That system held for nearly three decades until 1971 when Nixon ended dollar-to-gold convertibility. From that point forward, currencies became fiat. They have no intrinsic value. Their worth is based entirely on trust in the issuing government and central bank.
The shift to floating exchange rates created the forex market as we know it today. Banks began trading currencies with each other directly, and the interbank market became the backbone of global finance. The term “cable” for GBP/USD dates back to the 1800s when exchange rates were transmitted between London and New York via transatlantic submarine cables. Traders still use the term today.
The forex market now trades over six trillion dollars a day, making it the largest and most liquid financial market on earth. It dwarfs equity markets. The dominant currency is the US dollar, which sits on one side of roughly 88 percent of all trades. The euro is second, followed by the Japanese yen, British pound, and Swiss franc. These five currencies and their crosses make up the vast majority of global volume.
Currencies trade in pairs. When you buy EUR/USD you are simultaneously buying euros and selling dollars. Every currency trade is a relative bet. You are not just saying the euro will go up. You are saying the euro will go up relative to the dollar. This is what makes currency trading fundamentally different from stocks, where you are simply long or short a single asset.
The two primary ways currencies trade are spot and forward. Spot is immediate exchange at the current rate. Forwards are contracts to exchange at a future date at a rate agreed today. The forward rate is not a prediction of where the currency will be. It is a mathematical function of the interest rate differential between the two currencies. This is one of the most misunderstood concepts in finance and one of the most important.
What drives exchange rates is layered. At the deepest level it is interest rate differentials and trade balances. Countries with higher rates attract capital, which strengthens their currency. Countries running large trade deficits see their currencies weaken over time. But on top of those slow-moving forces sit positioning, sentiment, central bank intervention, and geopolitical shocks that can overwhelm fundamentals for weeks or months.
The most famous example is George Soros breaking the Bank of England in 1992. Soros identified that the British pound was overvalued within the European Exchange Rate Mechanism and built a massive short position. When the Bank of England could no longer defend the peg, the pound collapsed and Soros made over a billion dollars in a single trade. That event demonstrated that even sovereign central banks can be overwhelmed by market forces when the fundamentals are against them.
Understanding currencies is not optional for anyone operating in global markets. Every international transaction, every cross-border investment, every multinational earnings report is affected by exchange rates. Currencies are not just an asset class. They are the foundation on which all other asset classes are priced.
