Fixed, floating, official, and parallel exchange rates

Exchange rates are not always determined in the same way. Some currencies move freely in the market. Others stay near a value set by an authority. Some use intermediate systems. An official rate can also differ from the rate available in real transactions or parallel markets.

Understanding the exchange-rate regime is essential for interpreting a quote.

Floating exchange rate

Under a floating regime, the currency's value changes mainly through supply and demand in foreign-exchange markets.

Authorities can sometimes intervene by buying or selling currencies. They do not necessarily promise to maintain a specific parity. Movements are called appreciation and depreciation.

A float allows the exchange rate to absorb some economic changes. It can also produce rapid movements and pass uncertainty to importers, exporters, borrowers, and consumers.

Fixed exchange rate

Under a fixed regime, an authority sets a parity against another currency, a basket, or an asset. To support it, the central bank can buy or sell reserves, change interest rates, or place conditions on access to foreign currency.

A fixed rate reduces nominal movement while it remains credible and sustainable. It also limits monetary-policy independence and requires resources when supply and demand differ sharply at the set price.

If the authority officially lowers the parity, it devalues the currency. If it raises the parity, it revalues the currency.

Intermediate and managed regimes

Many systems exist between a fully free float and a rigid peg:

Bands within which the rate can move.
Parities that adjust gradually.
Managed floating with frequent intervention.
A link to a currency basket.
Different rates for different transactions.

Classifying a currency only as “fixed” or “floating” can therefore hide important details.

Official rate and reference rate

An official rate is set or recognized by an authority for specified transactions, records, or conversions. A reference rate can be an informational average published by a central bank without being the final transaction price.

Availability matters as much as the number. A rate can appear in an official publication without being available to every person, amount, or use.

Taxes, limits, authorizations, or different rates can also apply to imports, tourism, exports, savings, or financial payments.

Why parallel markets appear

A parallel market can develop when foreign-currency demand cannot be met at the official rate or when access is substantially restricted.

Buyers and sellers agree on another price in that market. The difference between the parallel and official rates is often called an exchange-rate gap or premium.

Parallel markets do not all have the same legal status. Some are informal or illegal. Others form part of recognized multiple-rate systems. The source's nature determines how the data should be interpreted.

What a wide gap can indicate

A persistent gap can indicate that the official price does not balance available supply and demand. It can also reflect controls, reserve shortages, uncertainty, transaction costs, or segmentation among different uses.

The gap can affect prices and economic decisions. Businesses without access to the official rate can calculate costs with an alternative quote. Exporters and remittance recipients can seek the channel that provides more local currency. These behaviors can reduce the official rate's usefulness as a general reference.

Which rate should a comparison use?

There is no universal answer. It depends on the question.

A legal or accounting obligation can require the official rate.
An accessible market rate can better estimate a transaction available to the public.
A historical series can use one consistent institutional source.
Several clearly labeled rates can show the divergence.

Each historical series identifies the selected rate, source, and purpose. If it combines official and parallel series, it marks the change explicitly.

When several rates are relevant, they should be treated as separate scenarios or references. One should not be presented automatically as the currency's only true value.