Currency Peg

A currency peg (also called a fixed or pegged exchange-rate regime) is a monetary policy under which a country's central bank or government commits to maintaining its currency's exchange rate at, or within a narrow band around, a chosen anchor — most commonly another currency (such as the US dollar or euro), a basket of currencies, or historically gold. The peg is sustained through active intervention: the central bank buys or sells foreign-exchange reserves to absorb supply-and-demand imbalances, and it uses interest-rate policy to align domestic monetary conditions with the anchor. Pegs span a spectrum of rigidity. A "hard peg" leaves little or no room to deviate and includes arrangements such as a currency board (where domestic money is fully backed by foreign reserves, as in Hong Kong's link to the US dollar) or outright dollarization (adopting a foreign currency entirely). A "soft peg" allows a managed band or an adjustable target, and a "crawling peg" lets the rate move gradually along a pre-announced path. The central trade-off is captured by the economic "trilemma" (or impossible trinity): a country generally cannot simultaneously maintain a fixed exchange rate, free movement of capital across its borders, and an independent monetary policy — it must give up one. The defining vulnerability of a peg is that defending it consumes finite reserves; if markets doubt the central bank's ability or willingness to hold the line, speculative pressure can force a devaluation (lowering the official rate) or a complete abandonment of the peg, often abruptly. Famous episodes in market history include the United Kingdom's exit from the European Exchange Rate Mechanism on "Black Wednesday" in 1992, the Asian financial crisis of 1997–98 (when several dollar pegs broke), Argentina's collapse of its currency board in 2001–02, and Switzerland's removal of its minimum exchange rate against the euro in January 2015. A peg shapes how an exchange rate is allowed to move; it does not eliminate the underlying economic forces, and a broken peg can produce some of the fastest, largest currency moves in financial history.

In plain English — A currency peg is a promise by a government or central bank to keep its money trading at — or very close to — a set rate against something else, usually a major currency like the US dollar or euro. Instead of letting the open market decide the exchange rate minute by minute (a "floating" currency), the authorities commit to a target, such as "1 dollar = 7.8 of our currency," and then defend that target. They defend it by buying or selling their own currency using reserves of foreign money and gold, and by adjusting interest rates: if the currency is under pressure to weaken, the central bank sells reserves to buy it back and props the price up. The catch is that this promise is only as strong as the reserves and the credibility behind it. Pegs are a recurring character in market history because, when a country can no longer afford to defend the rate, the peg can snap suddenly — a "currency crisis" — and the exchange rate jumps to a very different level overnight. So a peg looks like stability on the surface, while quietly building up pressure underneath. This entry is educational only and is not a prediction about any currency.

Consider a simplified, hypothetical country, "Republica," whose central bank pegs its currency, the "rep," at a fixed rate of 10 reps per 1 US dollar. These figures are illustrative only and do not describe any real country or constitute a recommendation. As long as everyone believes the peg will hold, a forex trader can buy or sell USD/REP near 10.00 with very little day-to-day movement — the chart looks almost flat, far calmer than a typical floating pair. Now imagine economic stress builds: Republica runs low on the foreign-currency reserves it needs to defend the rate, and traders begin to suspect the peg cannot last. Speculators and ordinary holders rush to sell reps for dollars before any change, which forces the central bank to spend reserves buying reps to keep the price at 10.00. Reserves drain. One morning the central bank announces it can no longer hold the line and devalues the peg to 15 reps per dollar — or lets the currency float entirely, and it quickly slides to 18. A trader who was holding reps overnight now finds each rep buys far fewer dollars than the day before, and the move happened as a single gap, not a gentle slide. Crucially, a stop-loss order placed at, say, 11.00 would not have filled near 11.00, because the price jumped straight past it to 15 or beyond — so the actual exit (and loss) can be far worse than the level the trader chose. This is "gap risk": the deceptive calm of a peg can mask the possibility of one enormous overnight move when it breaks. The same dynamic appears in real history — for instance, when Switzerland abruptly removed its minimum exchange rate (a floor of 1.20 francs per euro) in January 2015, the franc surged within minutes and many traders' stops filled far from their intended levels. All numbers here are hypothetical and for education only.