A currency peg looks like the one thing that makes forex trading pointless. A central bank commits to holding its currency at a fixed rate against another, and the movement that traders live on is squeezed out by design. So can a pegged pair be traded at all? The answer is less obvious than it seems, because a peg does not remove risk. It changes its shape.
This article explains what a currency peg is, which pegs a retail trader actually meets, what trading one involves, and what happens on the rare day a peg gives way.
What a Currency Peg Is
A currency peg is an exchange rate regime in which the value of a currency is tied, more or less rigidly, to another currency or to a basket. The anchor is usually a currency that is stable or dominant in the country's trade, which in practice means the US dollar or the euro. To hold the rate, the central bank buys or sells currency in the market, moves interest rates, and draws on its foreign exchange reserves.
Pegs are far more common than the floating majors suggest. In the International Monetary Fund's most recent survey of exchange arrangements, which describes the situation as of 30 April 2023, 13.4% of its members ran hard pegs, meaning a currency board or no national currency at all, and another 44.8% ran soft pegs of various kinds. Floating regimes accounted for 32.5%. The dollar was the anchor for 38 countries and the euro for 25. The modern floating system is itself the child of a broken peg, the Bretton Woods system that ended in the early 1970s.
Countries peg to import price stability, to make trade and investment easier to plan, and to borrow the credibility of a stronger currency. The price is monetary independence. Economists call it the trilemma, or the incompatible trinity in the words of the Nobel committee that honored Robert Mundell in 1999: with capital free to move, monetary policy can target the exchange rate or domestic conditions, but not both at once. A country that pegs to the dollar largely imports US interest rates, whether or not they suit its economy.
Peg, Band or Managed Float?
A peg is not always rigid to the last decimal. Some regimes let the rate move inside a declared band, and the narrower the band, the greater the commitment needed to hold it. Others defend a single level.
A peg should not be confused with a managed float. In a managed float the currency is left to supply and demand, and the central bank steps in from time to time when it judges a move excessive or unwelcome. In a peg there is an explicit level or range that the authority undertakes to defend. Intervention is occasional in the first case and part of the machinery in the second.
The labels matter, because currencies that traders lump together as pegged sit in very different places. In the IMF's classification Hong Kong runs a currency board, one of the two hard forms. Denmark and Saudi Arabia run conventional pegs, which count as soft pegs. Singapore, which manages its dollar against a trade-weighted basket, is classified as a crawl-like arrangement, a category the IMF also files under soft pegs even though the rate is allowed to trend. China is the one that falls outside the peg categories altogether, in the residual group of other managed arrangements.
The Pegs a Retail Trader Actually Meets
The best-known example is the Hong Kong dollar. Since 17 October 1983 it has been linked to the US dollar through a currency board, and today it trades inside a band of 7.75 to 7.85 per US dollar. The mechanism is automatic. When the rate reaches 7.75, the strong side, the Hong Kong Monetary Authority sells Hong Kong dollars for US dollars; the banking system's cash balance, which the HKMA calls the Aggregate Balance, expands and local interest rates fall. At 7.85, the weak side, it buys Hong Kong dollars, liquidity shrinks, interest rates rise and holding the currency becomes attractive again.
The Danish krone is the European case. Denmark has run a fixed exchange rate policy since 1982, first against the Deutsche Mark and then against the euro, with a central rate of 7.46038 kroner per euro and an agreed band of 2.25% on either side. The krone actually uses a fraction of that room. Over the twelve months to 18 September 2026, the European Central Bank's daily reference rate for EUR/DKK stayed between 7.4635 and 7.4759. The median day-to-day move was 0.004%, against 0.19% for EUR/USD, about 47 times as much.
The Gulf provides the third group. Saudi Arabia has kept the riyal at 3.75 per dollar since June 1986, and the other Gulf monarchies run conventional dollar pegs as well, with the exception of Kuwait, which manages the dinar against an undisclosed basket.
Can You Trade a Pegged Pair?
In theory, yes. In practice the peg changes almost everything about the trade.
Volatility is tiny, so strategies built on wide directional moves have nothing to work with. A pair like EUR/DKK, whose typical day-to-day move is about three pips, leaves very little once spreads, commission and overnight financing are paid, because trading costs do not shrink with the range. The same arithmetic applies to USD/HKD, which the pip value calculator covers: putting the value of a few pips into the account currency before the trade shows how they compare with the size of the move being targeted.
The trade that does exist inside a credible band is driven by interest rates, and Hong Kong gave a textbook demonstration in 2025. In early May the rate hit 7.75 four times in three trading days, and the HKMA sold HK$129.4 billion. The Aggregate Balance almost quadrupled within days, from about HK$45 billion to HK$174 billion, and the one-month interbank rate collapsed from an April average of about 3.65% to under 1%. With US dollar rates above 4%, borrowing Hong Kong dollars to hold US dollars became an attractive carry trade, and the HKMA itself said so. The rate slid across the whole band and reached 7.85 on 26 June. Between late June and mid-August the weak side was triggered twelve times, and the HKMA bought back HK$119.9 billion.
The whole band is about 1.3% wide. A trader who rode it from edge to edge earned that, plus the interest differential, against a loss that was bounded as long as the band held. That last condition is the entire trade, and it explains the risk profile of pegged currencies in general: long periods of very low ordinary volatility, and a small probability of an extreme move. A pegged pair is not a low-risk pair. Its risk is simply distributed differently.
When a Peg Breaks
The modern reference is not a classic peg but a one-sided floor. On 6 September 2011 the Swiss National Bank set what it called a minimum exchange rate of 1.20 francs per euro and declared itself ready to buy foreign currency in unlimited quantities. On 15 January 2015 it dropped the policy without warning. The ECB's daily reference rate for EUR/CHF went from 1.2010 to 1.0280 in a day, a fall of 14.4%, and reached 0.9816 about a week later. The day the SNB abandoned its floor is told in full in the article on safe haven currencies.
The consequences for retail trading were severe. With almost no liquidity on the way down, stop-loss orders were filled far from their levels, a violent form of slippage, and many accounts ended with negative balances. FXCM, then a large US-listed retail broker, reported client debts of about $225 million that day, a figure that rose to $276 million in its audited accounts, and needed a $300 million rescue loan. Alpari UK went into administration on 19 January. Interactive Brokers put its unsecured client debts at about $129 million after hedging.
Classic pegs have broken just as abruptly. Sterling was forced out of the European Exchange Rate Mechanism in September 1992. Thailand floated the baht on 2 July 1997, and the currency lost about 19% against the dollar in a single day, the rate going from 24.52 to 30.18 baht per dollar. By 12 January 1998 it took 56.10 baht to buy a dollar, and the currency had lost more than half of its value in a little over six months. More recently, tightly managed official rates have been let go abruptly when the authorities merged them with the parallel market: the Egyptian pound fell 38% on 6 March 2024, the day unification began; Ethiopia's birr went from about 57.5 to 74.7 per dollar on 29 July 2024 and on to about 119 within eight weeks; and Nigeria's naira, after its official windows were merged in June 2023, went from 461 per dollar in May of that year to about 900 by December.
Brokers drew their own conclusions. In its annual report for 2014, FXCM told investors that it had removed currency pairs managed "by a floor, ceiling, peg or band" and had raised margin requirements, noting that currencies such as the Danish krone had become less liquid. It is one reason pegged and managed pairs can carry higher margin requirements than the majors.
What to Watch on a Pegged Currency
The first thing to establish is which side the pressure is on. A central bank resisting appreciation can create its own currency without limit. Denmark made the point in early 2015, when capital poured into the krone after the Swiss move: the central bank cut the rate on its certificates of deposit four times in under three weeks, to −0.75%, and bought foreign currency worth 274.9 billion kroner in two months, while the Ministry of Finance, on the central bank's recommendation, suspended the issuance of government bonds. As the central bank noted at the time, there is no upper limit to the size of a foreign exchange reserve. A central bank resisting depreciation is spending reserves that are finite, which is why most of the breaks above went in that direction. The Swiss case shows that even the first kind of commitment can be dropped when its cost grows large enough.
The second is the soundness of the central bank and the economy behind it: ample reserves, inflation under control, balanced external accounts and institutional credibility make a peg sustainable, while falling reserves, large deficits or political tension do the opposite. Inflation is the slow-moving threat. If prices rise faster at home than in the anchor country while the nominal rate stays fixed, the currency becomes steadily more expensive in real terms, which is the kind of drift the real effective exchange rate captures.
The third is interest rates. Defending a weak currency may mean raising rates to make it worth holding, and resisting a strong one may mean cutting them below zero, so rate differentials become a central part of the trade.
The fourth is the forward market. Forward points reflect, first of all, the interest rate differential between the two currencies, a relationship known as covered interest parity. The relationship is not exact, and funding pressures pull forwards away from it routinely, but on a pegged currency a premium far wider than the rate gap is usually the market paying for protection against a devaluation. In January 2016, with oil collapsing, twelve-month forwards on the Saudi riyal rose above 1,000 points for the third time in a month, and the Saudi central bank told banks to stop selling options on riyal forwards. The peg held at 3.75. Forward stress is a warning, and it is not a verdict.
Low Volatility, Different Risk
A currency peg does not make forex trading impossible. It makes it a different activity: smaller moves, costs that weigh more, a carry component that comes and goes with interest rates, and an event risk that no stop-loss fully covers. The limits of a band are a policy, and policies change. Treating them as an infallible barrier is the one mistake a pegged currency does not forgive.
