My friend sent me a photo of Lebanon last week. He was holding a bundle of banknotes that looked like Monopoly money—more than 50,000 Lebanese pounds, which is about R$ 3. That made me think: while here in Brazil we complain about the dollar, there are places where the population simply lives with coins that have lost all their value. And it’s not an exaggeration.

We hear that the real was the worst currency in the world in 2024, with a drop of more than 20%. It sounds scary. But when you see what happens in other countries, you realize we’re doing much better than many people out there. There are currencies so weak that the citizens themselves prefer to keep dollars under the mattress rather than trust the national currency. That’s a sign that something is seriously wrong.

What makes a currency become the cheapest in the world? It’s never an accident. There’s always a combination of factors: uncontrolled inflation (imagine prices doubling every month), constant political instability (coups, wars, governments that don’t last), economic sanctions that isolate the country, lack of international reserves at the central bank, and, last but not least, that panic where even local residents flee the national currency.

Using data from 2025-2026 as a reference, the Lebanese Pound is the absolute champion. Officially it should be 1.507 pounds per dollar, but in real life on the streets you need more than 90,000. Banks limit withdrawals, shops only accept dollars, and an Uber driver asks for payment in dollars. The cheapest currency in the world has basically become useless.

Then there’s the Iranian Rial. With R$ 100, you become a millionaire in rials. American sanctions destroyed confidence in the currency. What’s interesting is that many Iranians moved to Bitcoin and Ethereum—cryptocurrencies became a more reliable store of value than the country’s own currency.

The Vietnamese Dong is another interesting case. Vietnam has a growing economy, but the dong has always historically been weak. For tourists it’s great (you withdraw 1 million dongs and feel rich), but for Vietnamese people it means imports become expensive. The same story applies to the Indonesian Rupiah—Indonesia is the largest economy in Southeast Asia, but its currency has never managed to strengthen since 1998.

There’s also the Laotian Kip, Uzbek Sum, Guinean Franc (a country rich in gold but with a weak currency because of political instability), Paraguayan Guarani (our neighbor that keeps its currency traditionally weak), Malagasy Ariary (Madagascar is one of the poorest nations), and the Burundian Franc closing the ranking—so weak that people literally carry bags of money for big purchases.

The pattern is clear: the cheapest currency in the world always reflects a fragile economy. Unstable politics, corruption, and lack of trust in institutions. When an investor sees that, they run.

For those who invest or travel, here are some lessons. First: devalued currencies may look like a cheap opportunity, but the truth is that these countries live through deep crises. Second: tourism in destinations with weak currencies really becomes cheaper—you arrive with dollars or reais and your money goes further. Third: watching currencies plummet is a practical way to understand how inflation, corruption, and instability affect people’s everyday lives.

What’s important is to remember that a strong economy depends on stability, trust, and good governance. When those pillars fall, the currency falls too. And yes, understanding this helps us think more carefully about where to put our money in the long run.