The foreign exchange market—forex, or FX—is the world's largest financial market, with average daily turnover of $9.6 trillion as of April 2025 according to the Bank for International Settlements (BIS) Triennial Central Bank Survey[reference:0][reference:1]. This guide explains what forex is, how it works across the globe, who uses it and why, how to evaluate brokers and platforms, and the critical risks every participant should understand.
Forex (foreign exchange) is the global, decentralised marketplace where currencies are bought, sold, and exchanged. Unlike stock exchanges that operate in a single location, forex trades over-the-counter (OTC) through a global network of banks, brokers, and financial institutions. Trading runs 24 hours a day, five days a week, across financial centres from Sydney and Tokyo to London and New York[reference:2].
The BIS Triennial Central Bank Survey—the most comprehensive source of information on global OTC FX markets—reported that turnover in OTC FX markets averaged $9.6 trillion per day in April 2025, a 28% increase from $7.5 trillion in 2022[reference:3]. The survey, coordinated by the BIS under the auspices of the Markets Committee, collected data from more than 1,100 banks and other dealers across 52 jurisdictions[reference:4][reference:5].
Forex trading revolves around currency pairs. Each trade involves buying one currency (the base currency) while simultaneously selling another (the quote currency). The exchange rate between the two determines the price. For example, in the EUR/USD pair, the euro is the base currency and the US dollar is the quote currency. If EUR/USD rises from 1.1000 to 1.1050, the euro has strengthened against the dollar.
Globally, the US dollar dominates the forex market. According to the BIS, the dollar was on one side of 89.2% of all trades in April 2025, up from 88.4% in 2022[reference:7]. The euro (28.9%), Japanese yen (16.8%), and sterling (10.2%) follow, while the Chinese renminbi and Swiss franc have increased their shares[reference:8].
Forex is traded through several instruments, including spot transactions (immediate delivery), outright forwards (agreed future exchange at a fixed rate), FX swaps (simultaneous spot and forward transactions), and options. In 2025, FX swaps remained the most traded instrument at $4 trillion per day, though their share fell to 42% as spot and forwards grew faster[reference:9].
The forex market is composed of a diverse range of participants, each with different objectives and levels of influence[reference:10].
Central banks (e.g., the Federal Reserve, ECB, Bank of Japan) intervene in forex markets to manage monetary policy, stabilise their currencies, or influence inflation and trade balances[reference:11].
Banks act as market makers, facilitating currency trading for clients and their own proprietary desks. They account for the largest share of daily volume[reference:12].
Companies with international operations use forex to convert earnings, pay suppliers, and hedge against currency risk that could affect profits[reference:13].
These participants trade forex for speculative returns and portfolio diversification. They often use sophisticated strategies and significant leverage.
Individual investors trade forex through online brokers. While they represent a small fraction of total volume, retail participation has grown significantly with the rise of digital trading platforms.
Forex serves a wide range of practical purposes beyond speculation. Here are the most common use cases across the global economy.
Exporters and importers use forex to convert payments between currencies. A US-based company selling goods to Europe receives euros and needs to convert them to dollars. Fluctuations in exchange rates can significantly affect profit margins, making currency management essential.
Businesses use forward contracts and options to lock in exchange rates for future transactions. For example, a UK manufacturer with a large contract in US dollars might use a forward contract to fix the GBP/USD rate, providing budget certainty and protecting against adverse movements[reference:15].
Institutional investors and fund managers trade forex to diversify portfolios, gain exposure to foreign assets, or hedge international investment positions. Currency movements can either enhance or erode returns on overseas investments.
Central banks may buy or sell their own currency to influence its value, combat inflation, or support economic objectives. These interventions can have significant, though often temporary, effects on exchange rates[reference:16].
Choosing a forex broker is one of the most critical decisions for any participant. The CFTC and NFA strongly emphasise the importance of due diligence before depositing funds[reference:17]. Use the following criteria to evaluate any broker or platform.
Always verify that the broker is registered with a reputable regulator in your jurisdiction. In the US, check CFTC registration and NFA membership via the NFA BASIC database, which provides comprehensive information on registration, disciplinary history, and financial standing[reference:18][reference:19]. In the UK, look for FCA authorisation; in Europe, CySEC or BaFin; in Australia, ASIC.
Compare spreads (the difference between bid and ask prices), commissions, and swap/rollover fees. A broker that is transparent about all costs is more trustworthy than one that hides fees in fine print[reference:20].
Test the trading platform for stability, speed, and usability. Reliable execution without excessive slippage or requotes is essential, especially for active traders[reference:21].
Confirm that client funds are held in segregated accounts and that the broker offers negative balance protection where required by regulation[reference:22].
The table below compares the main forex instruments used worldwide, based on BIS 2025 Triennial Survey data[reference:25].
| Instrument | Description | 2025 Daily Turnover | Share of Global Market | Typical Users |
|---|---|---|---|---|
| FX Swaps | Simultaneous spot purchase and forward sale | $4.0 trillion | 42% | Banks, corporations |
| Spot | Immediate delivery (T+2 settlement) | $3.0 trillion | 31% | All participants |
| Outright Forwards | Agreed future exchange at fixed rate | $1.8 trillion | 19% | Corporations, hedgers |
| Options & Other | Right (not obligation) to exchange at a rate | $0.8 trillion | 8% | Institutional investors |
Note: Turnover figures are rounded. Total exceeds $9.6 trillion due to the "net-net" basis of reporting. Data source: BIS Triennial Central Bank Survey, April 2025[reference:26].
Misunderstandings about forex are widespread, and they can lead to costly mistakes. Here are some of the most persistent myths.
Forex trading carries significant risk and is not suitable for all investors. The CFTC and NASAA warn that off-exchange forex trading by retail investors is "at best extremely risky, and at worst, outright fraud"[reference:30]. Leveraged products can result in losses that exceed your initial deposit[reference:31]. Never trade with money you cannot afford to lose.
Exchange rates are influenced by interest rates, inflation, political events, economic data, and market sentiment. These factors can cause sudden, sharp movements that are difficult to predict.
Leverage allows traders to control large positions with a small deposit, but it also magnifies losses. For example, a 1% adverse move on a 50:1 leveraged position can wipe out the entire margin[reference:32]. In Europe, leverage caps have been introduced to limit retail investor exposure[reference:33].
If a broker becomes insolvent or engages in fraudulent activity, client funds may be lost. This is why regulatory oversight and segregated accounts are essential. The CFTC has seen an increase in fraud complaints from customers who deposited large sums with unregistered offshore forex dealers[reference:34].
Emotional decision-making—fear, greed, and revenge trading—is a leading cause of losses. Discipline, a clear trading plan, and strict risk management are essential safeguards[reference:35].
Before engaging in forex trading or selecting a broker, work through this checklist.
Scenario: A UK-based manufacturer, BritCo Ltd, has secured a £5 million contract to supply machinery to a US client. Payment of $6.5 million is due in six months. The current GBP/USD exchange rate is 1.3000, which would give BritCo £5 million. However, the company is concerned that sterling might strengthen against the dollar, reducing the pound value of the payment.
Action: BritCo enters into a six-month forward contract with its bank to sell $6.5 million at a fixed rate of 1.2950. This locks in a proceeds value of approximately £5.02 million, providing budget certainty. If the spot rate moves to 1.3500 at maturity, BritCo has foregone a potential gain—but it has also eliminated the risk of a loss if rates moved to 1.2500.
Outcome: The forward contract successfully hedges BritCo's currency exposure, allowing the company to price its products confidently and protect its profit margin[reference:37].