Currency values move constantly in the global forex market, driven by a complex mix of economic, political, and psychological forces. This guide breaks down the key factors that cause exchange rates to rise and fall, explains how to interpret these drivers, and provides practical approaches for navigating currency markets with greater awareness.
At its core, the value of a currency is determined by the forces of supply and demand in the foreign exchange market. When demand for a currency exceeds supply, its price goes up. When supply exceeds demand, its price goes down. But what drives these supply and demand dynamics? The answer lies in a wide range of economic, political, and market-specific factors that influence how much of a currency traders, investors, businesses, and governments want to hold.
The foreign exchange market is the largest and most liquid financial market in the world. According to the Bank for International Settlements (BIS) Triennial Central Bank Survey, average daily trading volume exceeded $9.6 trillion in April 2025. This enormous scale means that even small changes in sentiment or policy can produce significant price movements.
Understanding what makes forex go up and down is not just academic — it is essential for anyone who trades currencies, does business across borders, or simply wants to understand the global economy. This guide will help you identify the key drivers and evaluate the forces that shape exchange rates.
Currency values respond to a combination of fundamental, technical, and psychological factors. Below are the most important drivers that determine whether a currency rises or falls.
Interest rates are perhaps the single most important factor influencing currency values. When a country's central bank raises interest rates, it typically makes that country's bonds and deposits more attractive to foreign investors, increasing demand for the currency and pushing its value up. Conversely, rate cuts tend to weaken the currency.
The interest rate differential — the gap between two countries' rates — is a critical metric. Traders watch central bank announcements from the Federal Reserve, the European Central Bank, the Bank of Japan, and other major institutions for signals of future policy changes.
Economic data releases serve as real-time snapshots of a country's economic health. Key indicators include:
When economic data exceeds expectations, the currency generally strengthens. Weaker data tends to weaken it — but the market's reaction also depends on how the data aligns with prevailing forecasts and broader sentiment.
Investors prefer to park their money in countries with stable political systems, transparent governance, and predictable policies. Elections, policy shifts, geopolitical tensions, and conflicts can increase uncertainty, prompting capital flight and weakening the affected currency.
For example, a contentious election, trade war, or military conflict can drive investors toward safe-haven currencies like the US dollar, Swiss franc, or Japanese yen, causing other currencies to drop.
Central banks can directly influence currency values through monetary policy decisions and, in some cases, direct intervention in the forex market. Quantitative easing (QE), interest rate guidance, and public statements by central bank officials can shape market expectations and trigger significant price moves.
Countries with large trade surpluses (exporting more than they import) tend to see their currencies strengthen over time, as foreign buyers need to purchase the local currency to pay for goods and services. Conversely, trade deficits can weigh on a currency's value.
Supply & Demand: Interest rates, economic data, inflation, trade flows, and central bank policies fundamentally determine currency valuations.
Market Perception: Trader sentiment, news narratives, risk appetite, and speculative positioning can amplify or counteract fundamental trends.
The drivers outlined above do not operate in isolation. They interact in complex ways, and their influence on a currency can change over time. Understanding how these interactions work is key to interpreting market movements.
Central banks often raise interest rates to combat inflation. Higher inflation can reduce a currency's purchasing power, but the expectation of rate hikes can strengthen the currency in the short term as investors anticipate higher returns. Conversely, if inflation remains high without rate hikes, the currency may weaken.
Markets price in expectations. If a rate hike is widely anticipated, the currency may have already strengthened before the announcement. This is why the deviation from expectations often drives price moves more than the actual data. When actual data surprises the market (either higher or lower), volatility typically spikes.
Currency movements are always relative. When the US dollar strengthens, it doesn't just affect USD pairs — it can also influence commodity currencies (like the Australian dollar, Canadian dollar, and New Zealand dollar), emerging market currencies, and cross-pair dynamics. Understanding these correlations is essential for a complete analysis.
Understanding what makes forex go up and down is not just theoretical — it has practical applications for different types of market participants. Below are three scenarios that illustrate how this knowledge is applied in real-world situations.
Situation: The Bank of England is scheduled to
announce its interest rate decision. The market expects a 25-basis-point
hike, but recent inflation data has been higher than forecast.
Action: A trader analyses the economic data and
central bank rhetoric. They anticipate that the BOE might take a
more hawkish stance than expected.
Outcome: When the BOE raises rates by 25 bps
and signals further hikes, the British pound strengthens against
the euro and dollar. The trader's understanding of the fundamental
drivers helps them profit from the move.
Situation: A European company that exports goods
to the US wants to protect its profit margins from an expected
weakening of the euro against the dollar.
Action: The company's treasury team monitors
European Central Bank policy signals, US economic data, and
interest rate differentials. They anticipate that the ECB will
cut rates while the Federal Reserve holds steady, widening the
rate gap.
Outcome: The company enters into a forward
contract to lock in a favourable exchange rate, protecting their
future revenue from the expected downward movement in EUR/USD.
Situation: A swing trader observes that oil
prices are rising sharply and that the Canadian dollar often
moves in tandem with crude oil.
Action: The trader combines their knowledge of
the oil-Canada correlation with an analysis of the Bank of
Canada's policy outlook and US dollar trends.
Outcome: They enter a long USD/CAD position,
anticipating that higher oil prices will support the Canadian
dollar relative to the US dollar. Their understanding of the
interconnected drivers helps them make an informed decision.
When evaluating whether a currency is likely to rise or fall, traders and analysts use a combination of fundamental analysis, technical analysis, and sentiment assessment. The following checklist outlines the key steps in a sound evaluation process.
| Driver Type | Key Factors | Time Horizon | Typical Impact |
|---|---|---|---|
| Fundamental | Interest rates, inflation, GDP, employment, trade balances | Medium to long term (weeks to months) | Trend-defining; sets the overall direction |
| Technical | Support/resistance, moving averages, chart patterns, momentum | Short to medium term (minutes to weeks) | Entry/exit triggers; confirms or contradicts fundamentals |
| Sentiment | News flows, market positioning, risk appetite, fear/greed | Short term (seconds to days) | Amplifies moves; can create overshoots or reversals |
Note: These categories often overlap, and their relative influence varies by market conditions. Always consider multiple perspectives.
Reality: While growth often supports a currency, it's not always the case. If growth is driven by excessive debt or inflation, it can actually weaken the currency. Market sentiment and expectations also play a role: if growth is already priced in, the currency may not respond positively.
Reality: Rate hikes are generally positive for a currency, but if they are seen as a response to economic weakness or if the market was already anticipating them, the currency may actually fall. The unexpected component of policy announcements often matters more.
Reality: Central banks have tools to influence their currencies, but they cannot dictate exchange rates in a free-floating market. Market forces, global capital flows, and external shocks often override policy intentions. The Federal Reserve itself acknowledges that exchange rates are determined by market participants.
Reality: A weaker currency can boost exports by making goods cheaper for foreign buyers, which can support economic growth and employment. Conversely, a strong currency can hurt export competitiveness. Whether a currency movement is "good" or "bad" depends on the economic context.
Reality: No model can predict exchange rates with certainty. The forex market is influenced by too many variables, including human psychology and unexpected shocks. The BIS notes that exchange rates are inherently difficult to forecast, and even sophisticated models have significant error margins.
Forex trading involves substantial risk and is not suitable for all investors. Leverage can amplify both gains and losses, and you may lose more than your initial investment. Currency markets can be volatile, and price movements can be sudden and unpredictable. Even with a strong understanding of what makes forex go up and down, you cannot eliminate risk.
The CFTC and NFA have warned that retail forex trading is complex and that traders should be fully informed of the risks before participating. Only trade with funds you can afford to lose.