Exchange rates on the open market change many times per second during active trading hours, but the rate a bank or exchange counter actually offers you updates far less often, often just once or twice a day, and carries a markup of 2% to 8% or more over the live market price. So the honest answer to how often do exchange rates change depends on which rate you mean: the interbank price is in near-constant motion, while your retail rate is a snapshot with a spread built in.
How Often Floating Currencies Reprice
Major currencies like the U.S. dollar, euro, British pound, and Japanese yen float, meaning their prices are set by supply and demand rather than fixed by a government. During active trading hours, those prices shift multiple times per second. The interbank market, where large financial institutions trade directly through electronic networks, drives the constant repricing. The Bank for International Settlements found average daily turnover of $7.5 trillion in its 2022 survey, a volume that guarantees prices never sit still for long.1Bank for International Settlements. OTC Foreign Exchange Turnover in April 2022
Automated systems amplify the movement. High-frequency algorithms make decisions in microseconds and process millions of orders per second, reacting to tiny imbalances between buyers and sellers faster than any human. The price of a currency at any given instant is really just the last trade that cleared; a millisecond later it is already different.
Trading Hours and When Rates Stop Moving
The forex market runs 24 hours a day from Sunday evening through Friday evening, with no centralized exchange. Trading flows through four overlapping sessions: Sydney opens first, then Tokyo, then London, and finally New York. Each handoff keeps prices updating as one financial center winds down and the next picks up. The heaviest volume and sharpest moves happen when London and New York overlap in the late morning and early afternoon Eastern Time.
Trading largely stops when New York closes on Friday at 5:00 PM Eastern and resumes Sunday at 5:00 PM Eastern as Sydney opens. Weekend gaps are real: if significant economic or political news breaks on a Saturday, rates can jump the moment trading restarts on Sunday evening. Traders call these gap opens.
Major holidays in key financial centers reduce activity even on days the market is technically open. When U.S., U.K., and Japanese markets all close on the same day, liquidity drops sharply and quotes become less reliable. When only one center is closed, the slowdown tends to show up mainly in pairs involving that country’s currency.
Not Every Currency Floats
Some governments peg their currency to a more stable one, usually the U.S. dollar, or to a weighted basket. Central banks hold these pegs by buying or selling reserves to keep the exchange rate within a narrow band. The IMF tracks these arrangements and notes that countries using conventional fixed pegs tie their rate to a major trading partner’s currency and intervene in the market to hold it there.2International Monetary Fund. Classification of Exchange Rate Arrangements and Monetary Policy Frameworks
Pegged currencies can go weeks or months without any visible change. Adjustments come only when the central bank or government formally revalues or devalues, and those adjustments tend to be sudden and significant when they do arrive. Day to day the rate feels stable; occasionally it lurches.
What Causes the Biggest Intraday Moves
Floating currencies do not move at a steady pace through the day. The sharpest swings cluster around scheduled economic releases and central bank decisions.
The U.S. Employment Situation report, often called the jobs report or Non-Farm Payrolls, is one of the most market-moving releases in the world. The Bureau of Labor Statistics publishes it monthly, typically on a Friday at 8:30 AM Eastern, though the exact date varies.3U.S. Bureau of Labor Statistics. Schedule of Releases for the Employment Situation Monthly Consumer Price Index data and quarterly GDP reports also move currencies, since both feed into expectations about whether the Federal Reserve will raise, lower, or hold interest rates.
The Federal Open Market Committee meets eight times a year to set rate policy, and each announcement can move currency markets sharply within seconds.4Federal Reserve. Meeting Calendars and Information Automated systems parse these releases the instant they hit and execute trades in microseconds. If you have any flexibility about when to exchange currency, avoid the minutes around a major data release. That is when prices are most erratic and retail spreads tend to widen.
Why the Rate You’re Offered Changes Less Often
The interbank rate, also called the mid-market rate, is the midpoint between the bid and the ask for a currency pair at any given moment. It is the fairest available price, free of any profit margin. You can check it in real time on sites like XE.com or through Google’s built-in converter.
You will almost never get the mid-market rate as a consumer. Every institution that exchanges currency for retail customers adds a spread. That spread is how they make money, and its size varies widely.
Traditional banks typically mark up the rate by 2% to 5%, sometimes more for less common currencies. Bank of America discloses that its offered rate “may be different from, and likely inferior to” the rate it pays to acquire the currency, and that the price includes profit, fees, and other markups set at the bank’s discretion. Banks generally set their retail rate once or twice per day rather than updating it in real time.5Bank of America. Foreign Exchange Rates for U.S. Dollars
Airport kiosks carry the worst rates you will find. Markups of 5% to 15% above the mid-market rate are common, because the captive audience of travelers in a hurry creates little competitive pressure. Most credit cards, by contrast, charge a foreign transaction fee of around 3% on purchases in another currency; some cards waive that fee entirely, which makes them one of the cheapest ways to spend abroad since the card network’s exchange rate usually sits close to mid-market. Online transfer services often offer tighter spreads than banks, sometimes under 1%, though the actual rate depends on the currency pair and the amount.
Dynamic Currency Conversion
When you use a credit or debit card abroad, the terminal or ATM may ask if you would like to pay in U.S. dollars instead of the local currency. This is dynamic currency conversion, and accepting it is almost always a bad deal. The merchant or ATM operator sets the exchange rate with a markup built in, and examples Mastercard publishes in its own merchant guidelines show markups ranging from 3% at point-of-sale terminals to 8% at ATMs.6Mastercard. Dynamic Currency Conversion Performance Guide That markup sits on top of any foreign transaction fee your card already charges. Choose the local currency and let your card network handle the conversion.
Timing and Rate-Shopping in Practice
Because the market rate moves constantly and the retail rate does not, a few habits change what you actually pay.
- Look up the mid-market rate on XE.com or Google before you exchange anything. That number is your benchmark for judging every offer.
- Use a credit card with no foreign transaction fee when spending abroad. Card networks convert close to mid-market, and with the fee waived your total cost is near zero.
- Skip airport and hotel exchange counters. If you need local cash on arrival, withdraw from an ATM with a debit card that has low international fees.
- Decline dynamic currency conversion every time. Pay in the local currency.
- For international transfers, compare the amount that actually arrives on the other end, not the headline fee. A low flat fee paired with a padded exchange rate often costs more than a higher fee with a tighter spread.
- Time large conversions carefully. Avoid exchanging during or immediately after a major economic release, when spreads widen. Midweek during the London and New York overlap, roughly 8 AM to noon Eastern, tends to offer the tightest spreads because liquidity is highest.