What is Currency Peg?
A currency peg is a policy where a country fixes its exchange rate to another currency (or basket of currencies) and uses central-bank intervention to maintain that rate. The Hong Kong Dollar is pegged to USD at 7.75–7.85; the UAE Dirham at 3.6725.
Definition
Currency pegs trade exchange-rate flexibility for stability. A country that pegs its currency commits to buying or selling the anchor currency in unlimited quantities to maintain the agreed rate. This requires substantial foreign reserves and disciplined monetary policy. Pegs come in degrees: hard pegs (no flexibility, e.g., HKD), soft pegs with bands (PBOC manages CNY within ±2% of a daily fix), and crawling pegs (the official rate slowly devalues over time, common in some Latin American history). Pegs can collapse when reserves run out or policy credibility erodes — the 1992 UK ERM crisis, the 1997 Asian Financial Crisis, and the 2015 Swiss Franc shock (SNB abandoned its EUR/CHF floor) are textbook examples. Hong Kong's peg has survived every crisis since 1983, including the 1997 Asian crisis and 2020 COVID stress, defended by $400B+ in HKMA reserves.
Worked example
Hong Kong Dollar peg to USD: 7.75–7.85 band. When USD/HKD approaches 7.85 (HKD weak side), the HKMA buys HKD and sells USD reserves — withdrawing HKD liquidity from the banking system, pushing HIBOR (Hong Kong interbank rate) higher, making it expensive to short HKD. Eventually arbitrageurs are forced to close short positions, pushing USD/HKD back toward 7.80. HKMA reserve usage data is published daily — a transparent defense mechanism that few central banks match.
Why it matters
Pegs matter for travelers and businesses planning around stable currencies. If you're sending money to or from Hong Kong, UAE, Saudi Arabia, or other pegged-currency countries, the USD-equivalent value is essentially fixed — no need to time the market. For broader macro context, pegs explain why some emerging-market currencies move in lockstep with USD while others swing wildly: pegged currencies inherit USD's monetary policy.
Frequently asked questions
Why do countries peg their currencies?
Several reasons: (1) reduce trade uncertainty for businesses; (2) borrow monetary-policy credibility from the anchor country (typically USD or EUR); (3) attract foreign investment by reducing currency risk; (4) for oil exporters, lock in the value of USD-denominated oil revenues. The trade-off is loss of independent monetary policy — pegged countries must follow the anchor central bank's rates or risk capital flight.
Which currencies are pegged to USD?
Hard pegs: Hong Kong Dollar (7.75–7.85), UAE Dirham (3.6725), Saudi Riyal (3.75), Qatari Riyal (3.64), Bahraini Dinar (0.376), Omani Rial (0.385), Cuban Peso (24). Soft/managed pegs: Chinese Yuan (managed band against basket), Singapore Dollar (against trade-weighted basket). The Argentine and Lebanese Peso have had partial pegs historically that broke.
Can a peg ever be broken?
Yes — when defending the peg costs more than the central bank can sustain. The 1992 UK ERM crisis cost the BoE billions defending GBP's peg to the Deutsche Mark before abandoning it. The 2015 SNB EUR/CHF floor break happened when defending the floor required printing too much CHF, threatening domestic inflation. Once a peg breaks, the currency typically falls 15–40% in days.
Related terms
Safe-Haven Currency
A safe-haven currency is one that investors buy during periods of global financial stress, often regardless of fundamental factors. The Japanese Yen (JPY), Swiss Franc (CHF), and US Dollar (USD) are the primary safe havens; gold is a non-currency safe haven.
Spot Rate
The spot rate is the current market exchange rate at which a currency pair trades for immediate delivery — technically settled two business days after the trade ("T+2"). It is what consumer converters and live rate dashboards display.
Interbank Rate
The interbank rate is the wholesale exchange rate at which major banks transact currencies among themselves. It is the foundation for all other rates and typically the tightest pricing available — institutional only.