The US Dollar's Role in Global Markets

What you will learn

• What a reserve currency is and why the dollar matters so much.
• The idea behind a dollar index.
• How dollar strength tends to affect gold, Bitcoin, commodities and stocks.
• Why these relationships have exceptions.

Explanation

A reserve currency is a currency that central banks and large institutions hold in big amounts as part of their reserves. The US dollar is the main reserve currency in the world. It is also widely used to price commodities, to settle international trade and to borrow internationally. Because so many prices and debts are in dollars, a change in the dollar can affect markets far outside the United States.

A dollar index measures the dollar against a basket of other currencies, not just one. The best-known version compares the dollar with several major currencies, and the euro has the largest weight in it. When the index rises, the dollar is stronger on average; when it falls, the dollar is weaker. Because the euro weight is large, the index often moves roughly opposite to EUR/USD.

Common tendencies when the dollar strengthens:

• Gold: gold is priced in dollars. A stronger dollar makes gold more expensive for buyers using other currencies, which can reduce demand. Gold also pays no interest, so rising US rates (often behind a stronger dollar) can make it less attractive.
• Other commodities: oil and metals priced in dollars can face similar pressure.
• Bitcoin and other crypto-assets: they have often behaved like risk assets. A strong dollar combined with tighter financial conditions has at times coincided with weaker crypto prices.
• Emerging markets: countries and companies with dollar debt find it more expensive to repay when the dollar rises.

Exceptions are common. In a crisis, investors may buy both the dollar and gold as safe havens. Crypto can move on its own news, such as regulation or technology events. Treat every link as a historical tendency, not a rule for the future.

Worked example

Hypothetical example: an investor in Germany looks at gold. Assumptions: round numbers only; fees, spreads, storage costs and taxes are excluded.

1. Start: gold = $2,000 per ounce, EUR/USD = 1.10. Price in euros: $2,000 ÷ 1.10 = €1,818.18.
2. Later: the dollar strengthens, EUR/USD = 1.00, and gold falls to $1,900.
3. Price in euros: $1,900 ÷ 1.00 = €1,900.00.
4. Change in dollars: ($1,900 − $2,000) ÷ $2,000 = −5%.
5. Change in euros: (€1,900.00 − €1,818.18) ÷ €1,818.18 ≈ +4.5%.

A US investor saw a loss, while the German investor saw a gain on the same ounce. The strong dollar both pressured the dollar price and raised the euro value.

Common mistake

Practice activity

On paper: Bitcoin is at a hypothetical $50,000 and EUR/USD = 1.25. Later Bitcoin is still $50,000 and EUR/USD = 1.00. What is the price in euros before and after? Then write one sentence explaining why a strong dollar does not always mean lower crypto prices.

Key takeaways

• The dollar is the main reserve currency and the pricing currency for many commodities.
• A dollar index measures the dollar against a basket; the euro has the largest weight.
• A stronger dollar tends to pressure gold, commodities, crypto and dollar borrowers.
• Exceptions happen, especially in crises; for euro investors the currency effect can change the result.

Next step

In the next lesson you will learn which economic data releases move markets and why the surprise against expectations matters most.