Skip to main content

1. Why the US Dollar Still Runs the World

If you trade global markets for any length of time, you eventually run into the same question in a dozen different disguises: why does almost everything — oil, gold, emerging-market debt, even the price of a used car in a country that has never touched a dollar bill — still get priced against the US dollar?

It's tempting to answer "because the US economy is big." That's true, but it's not the reason. The eurozone economy is comparable in size, and nobody prices oil in euros. Japan has run a technologically advanced economy for decades, and the yen still isn't the unit the world reaches for. Size alone doesn't explain dominance. What does is a specific combination of history, infrastructure, and incentive structures that reinforce each other — and understanding that combination tells you a lot about how currency markets actually move, not just why the dollar sits at the top of them.

It started as an accident of timing, not superiority

The dollar's rise wasn't planned as a permanent arrangement. At the 1944 Bretton Woods conference, the US held roughly two-thirds of the world's official gold reserves, simply because World War II had driven capital into the one major economy that hadn't been bombed. Pegging other currencies to the dollar, which was in turn pegged to gold, was a practical fix for a shattered postwar system — not a statement that the dollar was inherently superior.

The peg to gold ended in 1971. The dollar's role as the world's reference currency didn't. That gap is the first clue that something other than the gold backing was doing the real work.

Liquidity is the actual product being sold

Here's the part that matters for anyone trading: a reserve currency isn't chosen because a country is trustworthy in some abstract sense. It's chosen because it's liquid — meaning you can move enormous amounts of it in and out of positions without the act of trading itself moving the price against you.

US Treasury markets trade several hundred billion dollars a day. That depth means a central bank in Southeast Asia can park billions in reserves and know it can unwind that position on short notice without cratering the market it's selling into. No other government bond market — not German Bunds, not Japanese JGBs — offers that combination of size and depth. Liquidity compounds on itself: because everyone else uses dollars for settlement, using dollars is cheaper and faster, which gives everyone else more reason to keep using dollars. This is the same logic that keeps a dominant messaging app dominant even after better apps exist — the value isn't just the product, it's who else is already on it.

The oil market locked in the habit

A specific historical decision reinforced this network effect: in the early 1970s, the US negotiated with Saudi Arabia and other OPEC members to price oil exports exclusively in dollars, in exchange for security guarantees. Because virtually every country needs to buy oil, and oil was priced in dollars, virtually every country needed to hold dollars. This "petrodollar" arrangement meant demand for the currency was baked into a commodity that has no substitute in the short run. Even as the global energy mix shifts, the pricing convention it established has proven far stickier than the original strategic bargain that created it.

Why alternatives keep failing to dislodge it

Every few years, a challenger gets discussed seriously — the euro after its 1999 launch, the yuan as China's economy grew, a basket of BRICS currencies more recently. Each faces the same structural wall:

  • The euro lacks a single, unified bond market. Nineteen countries with different credit risk issue their own debt, so there's no single "eurobond" as deep and standardized as US Treasuries.
  • The yuan is not freely convertible. China maintains capital controls, so foreign holders can't move yuan in and out of China as easily as they move dollars in and out of the US. A reserve currency that can be trapped isn't a reserve currency.
  • A commodity-backed alternative solves nothing new — it just recreates the rigidity that made the original gold standard collapse in the first place, without adding liquidity.

None of these are permanent laws of physics. They're specific, fixable design flaws. But fixing them requires political trade-offs (like China giving up capital controls) that governments have so far been unwilling to make.

What this means if you actually trade

This history isn't trivia — it changes how you should read dollar moves. When the dollar strengthens sharply, it's frequently not a verdict on the US economy at all; it's a liquidity scramble, where global investors facing stress anywhere in the world reflexively move into dollars because dollar markets are the only ones deep enough to absorb the flow. That's why the dollar often rallies during global crises even when the crisis originates inside the US itself — the 2008 financial crisis being the clearest example.

Understanding the mechanism, rather than memorizing the correlation, is what lets you tell the difference between "the dollar is rising because the world is de-risking into liquidity" and "the dollar is rising because of genuinely US-specific strength." Those two situations call for opposite trading conclusions, even though the chart looks identical.

The bottom line

The dollar's dominance isn't a reflection of American virtue or a guarantee written into the laws of economics — it's a self-reinforcing system built on a 1944 accident, a 1970s liquidity advantage, and a petrodollar arrangement that outlived the strategic logic that created it. Systems like that can persist for a very long time after their original justification fades, precisely because everyone's individual incentive is to keep using what everyone else is already using. That's worth remembering the next time a headline declares the dollar's dominance is about to end — the question isn't whether the current system has flaws, it's whether any alternative has solved the specific liquidity problem the dollar solved eighty years ago.

Comments

Popular posts from this blog

10. Why Do Currency Exchange Rates Fluctuate

Open a currency chart and you'll see constant, restless movement — a exchange rate that never sits still for more than a few seconds during trading hours. Unlike a stock, a currency isn't a claim on a company's future profits, so the usual explanation for why prices move ("the company did well" or "the company did poorly") doesn't apply. A currency's value is relative by definition — it's always the price of one currency measured in terms of another — which means understanding why exchange rates fluctuate really means understanding what shifts the relative appeal of holding one country's money over another's. A currency's value is always a comparison, never a standalone number The first thing worth clarifying is that there's no such thing as a currency simply going up or down in isolation. When people say "the dollar is strong," they mean strong relative to some other currency or basket of currencies. This might so...

6. Why Does Inflation Happen

Everyone experiences inflation the same way: things cost more than they used to. But that observation, while accurate, describes the symptom rather than the cause. Prices don't rise on their own — they rise because something specific changed in the relationship between how much money is chasing how many goods, and that relationship can shift for more than one distinct reason, each with a different explanation and a different remedy. Money and goods are two sides of the same equation At its simplest, an economy is a constant negotiation between how much money exists and how much stuff that money can buy. If the amount of money in circulation grows faster than the amount of goods and services available to buy, each individual unit of money ends up representing a smaller share of the total stuff — so it takes more of it to buy the same item. This isn't a policy failure or a conspiracy; it's closer to basic arithmetic. If a country doubles its money supply overnight without d...

9. Why Portfolio Diversification Reduces Risk

"Don't put all your eggs in one basket" predates modern finance by centuries, but it took until the 1950s for anyone to prove mathematically why it works — and the proof turned out to be more interesting than the folk wisdom alone suggests. Diversification doesn't just spread out your bad luck. Under the right conditions, it can genuinely reduce your risk without costing you any of your expected return, which is a much stronger and stranger claim than "don't be reckless." Risk isn't just about how much an asset moves The intuitive way to think about risk is to look at how much a single investment's price bounces around — a volatile stock feels risky, a stable bond feels safe. That intuition isn't wrong, but it's incomplete, because it only looks at assets one at a time. The more complete picture asks a different question: when this asset falls, what tends to happen to the other assets in the portfolio at the same time? This second ques...