Dollar Milkshake Theory Explained [2026]

You may have heard the term “dollar milkshake theory” in financial news or investment forums. It’s a catchy phrase that’s caught the attention of big investors and money experts. But most people don’t fully understand what it means. I’ll explain exactly what this theory is. I’ll also tell you why some serious investors believe in it. And I’ll show you how it might affect your money and investments.

The dollar milkshake theory describes a scenario. In this scenario, the US dollar becomes much stronger than other currencies. This happens because US interest rates are higher than rates in other countries. To understand why this matters for your savings, you need to know how currency markets work. You also need to understand the economic forces that could make this happen.

The Origins and Core Premise of Dollar Milkshake Theory

Brent Johnson is the CEO of Santiago Capital. He explained this theory in a viral presentation around 2021. His core argument is simple but important. The US dollar will become very strong over the next few years. Johnson calls this a “milkshake” effect. It’s like the strongest drink pulling liquid from the others at the bar.

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The theory rests on several connected factors. First, much of the world’s money system uses US dollars. The Bank for International Settlements says the US dollar is used in about 88% of all currency trades worldwide (BIS, 2022). This means when more people want dollars, the dollar becomes more valuable. Second, the theory assumes the Federal Reserve will keep interest rates higher than other central banks. This makes dollar investments more attractive to people around the world looking for good returns. [1]

When interest rates go up, borrowing costs more money. Companies and countries that borrowed dollars when rates were low now face big problems. They must pay back their loans at higher rates. As the dollar gets stronger, their debts become even harder to pay. This creates a cycle that the theory says will get worse and worse.

How Global Dollar Debt Creates the “Sucking Sound”

To understand dollar milkshake theory, you need to know about global dollar debt. Outside the United States, about $12 trillion in dollar debt exists. Companies, governments, and banks around the world owe this money (IMF, 2023). This is a major weakness in the world’s money system. [2]

Here’s the key point: when these groups borrowed dollars, they expected the dollar to stay stable. They also expected interest rates to stay manageable. If the dollar becomes much stronger and US interest rates stay high, these borrowers face a double problem. They earn money in their own currencies. But they must pay back loans in dollars. If the dollar gets stronger, they need much more of their own money to pay back the same loan.

Think about a company in Europe that earns euros. If the dollar gets stronger, it needs more euros to repay its dollar loan. The same is true for governments in developing countries. They borrowed dollars to build roads and schools. If the dollar gets stronger, their debt becomes much larger in real terms. This creates urgent need for dollars worldwide. Companies must trade their own money for dollars to stay alive. This huge demand for dollars is what Johnson calls the “sucking sound.” It makes the dollar even stronger.

In my work analyzing money trends, this cycle works like panic in markets. First, the dollar gets stronger. This creates problems for people who borrowed dollars. They need more dollars. This creates more demand for dollars. The dollar gets even stronger. The theory says this could spiral until something breaks.

The Interest Rate Differential: Why the Fed Matters Most

Dollar milkshake theory depends on one key idea. The Federal Reserve will keep higher real interest rates than other central banks. Real interest rates are adjusted for inflation. When US rates are higher than rates in Europe or Japan, money flows toward dollar investments (Tucker, 2023).

Here’s a simple example: US Treasury bonds pay 4.5%. German bonds pay 1.8%. An investor around the world has a good reason to buy US bonds instead. If the dollar also gets stronger, the returns become even better. This creates what experts call a “carry trade.” People borrow money in low-rate currencies. Then they invest that money in high-rate dollar investments.

The big question is: how long can the Federal Reserve keep rates higher than other banks? This doesn’t cause too much damage? In the past, rate differences last because central banks have different goals. They face different economic conditions. The dollar milkshake theory assumes the US inflation problem will last longer than in other countries. This means the Federal Reserve must keep rates high for a longer time.

Historical Precedent and the Strong Dollar Scenario

The dollar has been strong before. In the early 1980s, Federal Reserve Chair Paul Volcker raised interest rates very high. He did this to fight inflation that was over 10%. The dollar became much more valuable. From 1980 to 1985, the dollar index rose about 50%. This measures the dollar against other major currencies. Eventually, this wasn’t sustainable. In 1985, major countries agreed to work together to change currency values (Eichengreen, 2019).

Dollar milkshake theory supporters say things are different now. The amount of global dollar debt is much larger. It’s spread across more countries. Today’s connected money system makes dollar strength more dangerous. When the dollar got stronger from 2014 to 2016, developing countries had serious problems. Countries that sell oil faced falling income. Oil is priced in dollars. [3]

This history shows why smart investors study dollar milkshake theory. The conditions seem different this time. They may be more fragile. We have huge amounts of global dollar debt. The money system has high use. Countries are less willing to work together. These factors could create new kinds of problems.

Market Implications and Investment Consequences

If dollar milkshake theory happens as supporters predict, several things would occur. First, investments that lose value when currencies weaken would suffer. This includes many stocks from developing countries. It also includes investments tied to raw materials and foreign dividend stocks. Second, dollar investments would do very well. This includes US stocks, US bonds, and US company bonds.

Third, and most serious, the money system could break down. Companies unable to pay back dollar loans would fail. Banks holding bad dollar loans could face serious problems. The whole credit system could freeze. This is similar to what happened in 2008. This is why the theory gets attention and criticism. It describes a possible worst-case scenario that could hurt investment portfolios badly.

For people building wealth, the effects are real. A portfolio with lots of international investments might not do well if the dollar gets stronger. A portfolio with many developing country investments faces more risk from dollar milkshake scenarios. On the other hand, investors with lots of dollar assets and US stocks would benefit. But this might happen during broader market problems.

Criticisms and Counterarguments to Dollar Milkshake Theory

Many mainstream economists disagree with dollar milkshake theory. Their main argument is about self-correcting market forces. As the dollar gets stronger, US goods become more expensive. Other countries buy less from the US. This economic pain would force the Federal Reserve to lower interest rates. This would reduce the rate difference that’s driving dollar demand. Markets would balance out before extreme problems occur.

A second criticism focuses on Federal Reserve behavior. The Federal Reserve must balance two goals. It must fight inflation and support jobs. If serious money problems developed, history shows the Federal Reserve would lower rates. This would stop the dollar milkshake scenario before it got too bad.

Also, critics say other currencies could become more popular. The Chinese yuan, the euro, or new payment systems could gradually reduce dollar use. Central banks might hold fewer dollars in their reserves. Change would be slow. But it would prevent the concentrated feedback loop the theory describes (Prasad, 2022). [4]

These arguments are strong. They come from economists with good track records. The dollar milkshake theory remains a possible but uncertain scenario. It’s not something most experts predict. This is important for your money planning. Don’t change your entire portfolio based on a scenario that might not happen.

Practical Implications for Your Investment Strategy

Given this uncertainty, how should you approach dollar milkshake theory? View it as one possible scenario among many. Use it to test whether your portfolio can handle different situations.

First, look at your current investments. What percentage is in dollars versus other currencies? How much do you have in developing countries? If your portfolio is heavily weighted toward foreign investments or developing countries, think about whether that matches your comfort with risk. Or did you just follow what others do?

Second, imagine a stress test. Suppose the dollar got 30% stronger against major currencies over five years. This matches what dollar milkshake theory predicts. How would your specific investments perform? Would foreign dividend stocks give good returns after currency changes? Would developing country bonds be worth it? This exercise shows where your portfolio is weak.

Third, diversify across currencies and regions. But do it for good reasons, not just because people say to. Diversification protects you from many scenarios. These include a weak dollar, a strong dollar, regional recessions, and world events. International investments still make sense for most long-term investors. But you should understand why you own them.

Fourth, think about protecting yourself if you own lots of foreign investments. Currency protection exists through contracts, options, and special funds. These have costs. But they provide insurance. Whether insurance is worth the cost depends on your comfort with risk and how long you’ll invest.

Finally, focus on what you can control. Don’t try to predict whether dollar milkshake theory happens. Instead, make sure you’re getting market returns through low-cost funds. Keep good diversification. Control your costs. Avoid making emotional decisions during market swings. These basics matter much more than being right about big economic theories.

The Broader Context: Why Macro Theories Matter

You might ask: why think about dollar milkshake theory if most economists doubt it? The answer is about how markets actually work. Markets look forward. They price in what people expect to happen. If enough smart investors start believing this theory, they change how they invest. This changes the market even if the theory is wrong.

This is why understanding the theory matters. You need to know what ideas might be driving money flows and market prices. If big investors move money away from developing countries based on dollar milkshake concerns, developing country investments might become cheap compared to their real value. On the other hand, if the theory influences investors, dollar investments might become expensive compared to their real value.

The theory also highlights real economic weaknesses. These include global dollar debt, different central bank policies, and high use in the money system. These deserve attention whether or not dollar milkshake theory specifically happens. Understanding these factors improves your money knowledge and decisions.

Conclusion: Incorporating Macro Uncertainty Into Your Financial Plan

Dollar milkshake theory presents an interesting but uncertain scenario. The US dollar becomes much stronger due to interest rate differences and global dollar debt. This creates money problems worldwide. It would require major portfolio changes. The theory is based on sound economic ideas. But mainstream economists raise fair questions. They believe market forces or policy changes would prevent extreme scenarios.

For individual investors building long-term wealth, don’t reorganize your entire strategy around this theory. Instead, understand the scenario. Recognize the economic weaknesses it highlights. Make sure your portfolio can handle multiple possibilities. Keep investments spread across regions and currencies. Watch interest rate differences between major economies. Stay informed about global dollar debt. Avoid putting too much in any one investment or currency. [5]

Remember: investment success comes mainly from what you control. Control your savings rate. Control your asset mix. Control your costs. Control your taxes. Control your behavior. These matter much more than predicting which big economic theory proves correct. The dollar milkshake theory is worth understanding. But it shouldn’t stop you from making decisions or push you toward extreme portfolio positions based on a worst-case scenario.

Last updated: 2026-03-24