Direct Answer

The foreign exchange market is where one currency is exchanged for another. A currency pair such as EUR/USD expresses the value of the base currency (EUR) in terms of the quote currency (USD). The market has several distinct layers: a large wholesale over-the-counter (OTC) market for institutions, a retail OTC dealer market for individual U.S. customers where the CFTC warns the customer is generally trading against the dealer, and regulated exchange-traded currency futures with centralized clearing. Spread, commission, slippage and financing are all separate costs. Margin is collateral against a notional exposure, not a statement of maximum loss.

By Swoopr Editorial Team

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Forex Trading & Currency Markets: How FX Works

The foreign exchange market, usually called forex or FX, is the market where one currency is exchanged for another. A quote such as EUR/USD is not a price for the euro by itself. It is a relationship: how many U.S. dollars are being quoted for one euro. That simple relationship sits on top of a market with several very different layers, distinct counterparty structures, and costs that go beyond the displayed spread. This hub explains how FX actually works before you analyze a trade or an international portfolio.

Key takeaways

Why forex matters even if you never become a forex trader

Currency risk is already present in many portfolios. A U.S. investor can buy a foreign stock that rises 8% in its home currency and still earn less than 8% in U.S. dollars if that foreign currency weakens against the dollar. A U.S. company can report strong overseas sales while translating those sales into fewer dollars. A commodity producer can have revenue linked to a globally traded dollar price while paying many operating costs in another currency. A bond investor can own a high-yielding foreign bond and discover that currency depreciation overwhelms the extra yield.

This is why Swoopr treats FX as part of investment literacy, not just a short-term trading niche. The global market is large because currencies sit underneath trade, cross-border investing, financing, hedging and central-bank activity. The Bank for International Settlements' 2025 Triennial Survey measured $9.6 trillion in average daily OTC FX turnover in April 2025, up from $7.5 trillion in the 2022 survey. Spot transactions were about $3 trillion per day, outright forwards about $1.8 trillion, and FX swaps about $4 trillion. The U.S. dollar was on one side of 89.2% of reported transactions.

Those numbers are useful for understanding scale, but they need context. The BIS survey is a global dealer-market measure. It includes institutional activity, interdealer transactions, corporate hedging and financing structures. It should not be described as "$9.6 trillion of retail forex trading per day."

Start with the quote, not the prediction

Every currency trade involves two currencies. In a pair written as BASE / QUOTE, the first currency is the base currency and the second is the quote currency.

For EUR/USD, EUR is the base currency and USD is the quote currency. A quote of 1.1600 means 1 euro is being quoted at 1.1600 U.S. dollars. If EUR/USD moves from 1.1600 to 1.1700, the euro has strengthened against the dollar. If EUR/USD falls from 1.1600 to 1.1500, the euro has weakened against the dollar.

That sounds elementary, but it prevents a common analytical mistake: discussing one currency as if it moves independently. Every FX thesis is relative. Suppose you believe inflation in the United States will cool. That could influence expectations for Federal Reserve policy and the dollar. But EUR/USD also depends on expectations for the European Central Bank, euro-area growth, risk appetite, capital flows and what the market had already priced. A correct view about one economy can still produce a wrong pair forecast when the other side changes more.

Swoopr rule: finish the sentence. Do not write: "The dollar should fall because rates may be cut." Write instead: "I expect the dollar to weaken against the euro over my chosen horizon because I expect the U.S.-euro rate differential to move more than the market currently prices, and I will invalidate that thesis if the relative policy path or growth data moves the other way." The second statement can be checked. The first is a story.

There is no single forex exchange

Stocks train many new investors to imagine one centralized exchange order book. FX is more fragmented.

Wholesale OTC FX

The largest part of the global FX market is over the counter. Banks, asset managers, hedge funds, corporations and other institutions transact through dealer relationships and electronic venues rather than one universal central order book. The FX Global Code, maintained by the Global Foreign Exchange Committee, describes principles of good practice for the wholesale FX market. The current Code was last updated in December 2024. It is not a law and does not replace local regulation; it is a set of global principles intended to support fair, liquid, open and appropriately transparent market functioning.

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U.S. retail OTC forex

The structure is different for an individual in the United States using a retail OTC forex dealer. The CFTC warns that, unless the customer is trading exchange-listed forex futures or options, the retail OTC customer is generally trading against the dealer. When the customer buys, the dealer is the seller; when the customer sells, the dealer is the buyer. The dealer controls the platform and the prices presented on it, subject to applicable regulation and business practices. That does not mean every registered dealer is acting fraudulently. It means the counterparty model should be understood before money is deposited. The CFTC advises prospective customers to verify registration and disciplinary history, read the account agreement, understand withdrawal policies, and be skeptical of offshore or social-media solicitations.

Exchange-traded currency futures and options

Currency futures are standardized contracts listed on an exchange and cleared through a clearinghouse. That structure is closer to other futures markets than to retail OTC spot forex. Swoopr's existing Futures hub explains contract multipliers, margin, daily mark-to-market and expiration. This distinction matters because "forex" can describe currency exposure without identifying the instrument. A spot-style OTC position, a currency future, an FX forward and an option can express related economic views while carrying different execution, financing, settlement and regulatory mechanics.

The main FX instruments

A currency exposure can be expressed through several different instruments, each with distinct mechanics.

Spot

A spot FX transaction exchanges one currency for another at a current market rate, with settlement conventions depending on the currencies and venue. Retail platforms may present a continuous leveraged position that looks like "spot forex," but the customer should read the dealer agreement to understand exactly how positions are rolled, financed and settled.

Outright forwards

A forward fixes an exchange rate today for an exchange at a future date. Companies often use forwards to reduce uncertainty around future receipts or payments. Example: a U.S. company expecting to receive euros in three months faces the risk that the euro weakens before those euros are converted to dollars. A forward can lock an exchange rate for the future conversion. The company gives up the benefit of a favorable currency move in exchange for more certainty.

FX swaps

An FX swap combines an exchange of currencies with a reverse exchange at a later date. FX swaps are heavily used for funding and liquidity management. BIS data show they remained the largest instrument category in the April 2025 survey. A beginner does not need to trade an FX swap to understand why it matters. It is part of the plumbing of global dollar and foreign-currency funding.

Options

Currency options provide rights tied to an exchange rate rather than the symmetrical obligation of a forward. Premium, strike, expiration, volatility and option Greeks become important.

Currency futures

Currency futures standardize contract terms on an exchange. They can be useful for investors who want transparent contract specifications and centralized clearing, but futures introduce contract multipliers, margin, mark-to-market, expiration and rollover decisions.

Who uses the FX market, and why?

Participants range from global banks to individual travelers, and their purposes differ substantially.

What moves a currency pair?

There is no single permanent formula. The useful framework is to identify relative expectations.

A price is not the same as an executable price

A chart can show a clean mid-price while an actual order experiences several costs.

This is why Swoopr's companion guide uses a Quote to Cost to Carry workflow. A trader who only understands the quote understands only the first third of the economic problem. See: Currency Pairs, Pips, Spreads & Rollover.

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Leverage: the small deposit illusion

Leverage makes a large notional exposure possible with a smaller amount of collateral. For U.S. Forex Dealer Members, NFA Financial Requirements Section 12 currently requires a minimum security deposit of 2% of notional value for a listed set of major currencies and 5% for other transactions, subject to the rule's details and NFA's ability to increase requirements under extraordinary conditions. A 2% requirement corresponds arithmetically to 50:1 notional-to-collateral. A 5% requirement corresponds to 20:1. That is not a recommendation to use maximum leverage, and a dealer may require more collateral.

Margin is not the risk budget. If $2,000 of required collateral supports $100,000 of notional exposure, the position is still economically exposed to movements on $100,000, not $2,000. A 1% adverse move in $100,000 of notional exposure is about $1,000 before financing and execution effects. The required deposit tells you how much collateral the position needs. It does not tell you how much you should be willing to lose.

The companion risk guide builds this into an Exposure Stack: notional, then margin, then invalidation distance, then execution gap, then financing, then portfolio correlation. See: Forex Risk Management, Leverage & Margin.

Worked example: reading a currency move correctly

Assume EUR/USD moves from 1.1600 to 1.1720.

The change in the quoted exchange rate is: 1.1720 - 1.1600 = 0.0120

For this pair, a pip is conventionally 0.0001, so the move is 120 pips.

Percentage move: 0.0120 / 1.1600 = approximately 1.03%

A headline might say "the euro rose about 1% against the dollar." That is a complete description of the price move, but not an explanation. A research process would then ask: Did expected Federal Reserve policy change? Did expected European Central Bank policy change? Did U.S. or euro-area data surprise relative to forecasts? Did a broad risk-on or risk-off move occur? Was the pair already heavily positioned? Did the move happen in liquid hours or around a thin-liquidity event? Did related bond yields confirm the interpretation? The purpose of these questions is not to force a neat story onto every move. It is to separate observable facts from interpretation.

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Worked example: international stock return versus currency return

Assume a U.S. investor buys a foreign equity fund. Over a year, the underlying foreign equities rise 10% in local-currency terms and the foreign currency falls 6% against the U.S. dollar.

The dollar return is not exactly 10% minus 6% because returns compound:

Dollar return = (1 + local return) x (1 + currency return) - 1

= 1.10 x 0.94 - 1 = 3.4%

The investor was right about the local stock market and still earned only about 3.4% before fund expenses and taxes because the currency move offset much of the local return. Now reverse the currency move. If the foreign currency strengthens 6%: 1.10 x 1.06 - 1 = 16.6%. Currency exposure can amplify or reduce foreign-asset returns. This is why international investing links directly to FX education even for readers who never open a retail forex account.

How to evaluate an FX thesis

Swoopr's recommended research sequence is deliberately mechanical.

  1. Name the pair and direction. Do not say "bullish euro." Say "bullish EUR/USD" or identify the instrument you actually mean.
  2. Define the horizon. A one-hour trade and a six-month macro thesis can be driven by different information.
  3. State the relative catalyst. What changes for the base currency relative to the quote currency?
  4. Ask what is already priced. Markets respond to surprises, not just levels. Consensus expectations matter.
  5. Define invalidation. What evidence would make the thesis wrong? A different policy path? A break in a macro relationship? A price level? A time limit?
  6. Model total cost. Spread, commission, likely slippage and financing should be included where relevant.
  7. Size from risk, not margin availability. The fact that a platform allows a large position is not evidence that the position is appropriate.
  8. Check portfolio overlap. Long EUR/USD, short USD/CHF, long gold, and long foreign assets can all contain related dollar exposures. Labels can differ while the underlying factor repeats.
  9. Verify the counterparty and rules. For U.S. retail OTC forex, check CFTC/NFA registration and disciplinary history before funding an account.

Common mistakes

Where to get exchange-rate data

For U.S. readers who need a primary public reference for exchange rates, the Federal Reserve publishes the H.10 release. The current release provides bilateral exchange rates and broad dollar indexes. A key detail is quote convention. The H.10 table expresses most currencies as currency units per U.S. dollar, while selected currencies are shown as U.S. dollars per currency unit. Do not copy a number into a calculation without checking the table's convention.

Misconceptions versus reality

MisconceptionReality
Forex is one giant centralized exchangeMuch of global FX is OTC; retail OTC and exchange-traded futures have different structures
A higher interest rate automatically strengthens a currencyMarkets price expected relative policy paths, not just today's rate
A 2% margin requirement means only 2% is at riskMargin is collateral against a larger notional exposure
The tightest displayed spread is always cheapestCommission, slippage and financing can change total cost
A stop sets maximum lossIt sets an intended exit trigger or level; the actual fill can differ
$9.6 trillion per day means retail traders move $9.6 trillionBIS turnover is a global OTC market measure across instruments and institutional participants
FX only matters to active currency tradersInternational stocks, bonds, companies and portfolios can all carry currency exposure

Practical checklist before analyzing or trading a currency exposure

  1. Write down the exact pair and instrument.
  2. Identify base and quote currencies.
  3. Confirm whether the venue is retail OTC, institutional OTC, futures or another structure.
  4. Verify the counterparty or exchange.
  5. Calculate notional exposure.
  6. Calculate the spread in money terms.
  7. Identify commission and financing.
  8. Define the thesis horizon.
  9. State what would invalidate the thesis.
  10. Estimate slippage or gap risk.
  11. Check related positions for hidden currency concentration.
  12. Verify current regulatory requirements and dealer registration.
  13. Record the thesis and assumptions before the trade.
  14. Review the result by separating thesis quality, sizing quality and execution quality.

Frequently asked questions

What is forex trading?

Forex trading is taking exposure to changes in the exchange rate between two currencies. The exact mechanics depend on the instrument. U.S. retail OTC forex is generally dealer-counterparty trading, while currency futures trade on regulated exchanges.

What is a currency pair?

A currency pair expresses the value of one currency in terms of another. In EUR/USD, EUR is the base currency and USD is the quote currency. A quote of 1.1600 means one euro is worth 1.1600 U.S. dollars at that price.

How big is the forex market?

The BIS measured average OTC FX turnover of $9.6 trillion per day in April 2025 across spot, forwards, swaps, options and other dealer-market transactions. It should not be interpreted as retail trading volume.

Is forex open 24 hours?

Global FX activity spans major financial centers across the business week, so trading can occur nearly around the clock on weekdays. Liquidity is not constant, and retail platform hours, holidays and rollover conventions can differ.

Is forex trading regulated in the United States?

Yes, but the rules depend on the product and participant. U.S. retail OTC forex is overseen under CFTC/NFA rules for registered firms, while exchange-traded currency futures operate under futures-market regulation.

What is the difference between forex and currency futures?

Retail OTC forex is generally a dealer relationship with no centralized exchange for the customer transaction. Currency futures are standardized exchange-listed contracts cleared through a clearinghouse, with contract specifications, margin and expiration rules.

Why do currency prices move?

Currency pairs can respond to relative interest-rate expectations, inflation, growth, risk appetite, capital flows, trade, policy changes, positioning and liquidity. The effect depends on expectations and on what happens to both currencies in the pair.

Every guide in this cluster

Swoopr Editorial Team

Swoopr's editorial team researches and writes investment education content. All articles follow the editorial policy, which requires primary-source citations, verified regulatory data and clear separation of education from personalized advice. Corrections can be submitted through the corrections process.

References

  1. Bank for International Settlements: OTC foreign exchange turnover in April 2025
  2. Commodity Futures Trading Commission: Eight Things You Should Know Before Trading Forex
  3. National Futures Association: Forex Transactions: Regulatory Guide
  4. National Futures Association: Financial Requirements Section 12: Security Deposits for Forex Transactions
  5. Global Foreign Exchange Committee: FX Global Code
  6. Federal Reserve Board: Foreign Exchange Rates: H.10