Pegged Currencies: How Fixed Exchange Rate Systems Work
Many countries fix their currency to the US dollar or another currency. Here's how currency pegs work and why they sometimes fail.
A currency peg (also called a fixed exchange rate) is a policy in which a country's central bank sets a fixed exchange rate between its currency and another currency or basket. Unlike floating currencies, which move freely with market forces, pegged currencies are maintained at a set value by government intervention.
How Pegs Work
To maintain a peg, a central bank stands ready to buy or sell its own currency in whatever quantity is necessary to hold the target rate. If the market would push the currency lower, the central bank buys its own currency (selling foreign reserves) to support demand. If upward pressure exists, it sells its own currency and accumulates reserves.
This requires significant foreign exchange reserves to defend successfully over time.
Why Countries Peg Their Currencies
Stability: Pegged currencies eliminate exchange rate uncertainty, which benefits trade and investment — particularly for small economies that are heavily dependent on a single trading partner.
Inflation Control: Pegging to a low-inflation currency like the US dollar can import that stability into a country with historically poor monetary discipline.
Tourism and Trade: Gulf states like Saudi Arabia and the UAE peg to the dollar, which simplifies oil trade (priced in dollars) and provides a stable environment for international business.
Famous Peg Failures
Some of the most dramatic events in financial history have been peg defenses that ultimately failed. George Soros's 1992 bet against the British pound (then pegged in the European Exchange Rate Mechanism) is the classic example — he made over $1 billion in a single day when the UK was forced to abandon the peg.
More recently, the Swiss National Bank's 2015 removal of the EUR/CHF floor caused the franc to surge 15–20% within minutes, causing enormous losses for traders who had assumed the peg was permanent.
How This Affects Your Conversions
For currencies with a dollar peg (AED, HKD, SAR, and others), the exchange rate with the dollar is essentially fixed — your conversion will be predictable and stable. For floating currencies, expect more variability.