CDI

Key points

• CDI stands for Certificado de Depósito Interbancário (Interbank Deposit Certificate), tied to the interest rate on very short-term loans between banks.
• This rate became the main reference benchmark for the yield of post-fixed investments in Brazil.
• CDI is a traditional market benchmark and does not, by itself, describe the behavior of crypto assets.

What is CDI?

CDI is the Interbank Deposit Certificate, an instrument tied to the very short-term loans that banks make to one another. From these loans comes an interest rate, commonly called the CDI rate, which closely tracks Brazil's benchmark interest rate. Over time, this rate became a broad benchmark in the national financial market.

How it works

Banks need to close each day with their accounts balanced, and to do so they lend funds to one another for very short periods. The average rate of these loans is the CDI rate. Because it reflects the short-term cost of money and moves closely with the benchmark interest rate, it became a convenient gauge of the prevailing interest rate level in the country.

From there, CDI became a comparison parameter. Many fixed-income investments express their yield relative to it, saying they yield a percentage of the CDI. This allows alternatives to be compared in a standardized way and serves as a reference for assessing whether an investment's return is competitive against the cost of money in the economy. Because it is a closely tracked rate, it functions as a familiar comparison point for many Brazilians.

It is important to separate this concept from the crypto universe. CDI is a reference from the traditional interest rate market and does not describe the behavior of cryptocurrencies or stablecoins. In particular, the existence of a reais-denominated stablecoin, such as BRLP, does not imply a yield tied to CDI: a stablecoin seeks to maintain parity with the real, not to pay the CDI rate. Treating the two as equivalent is a mistake that should be avoided.

Understanding CDI helps interpret yield comparisons without improperly transferring them to assets that follow a different logic.

Why it matters

Understanding CDI helps interpret how the Brazilian market compares yields, and avoids confusing traditional fixed-income benchmarks with the behavior of crypto assets. Making clear that a reais-denominated stablecoin does not yield CDI prevents mistaken expectations. This is an educational explanation and does not represent any investment or trading recommendation.

Risks and limitations

CDI is a traditional market benchmark and does not apply to crypto assets, whose behavior follows a different logic. Using it as if it described the yield of stablecoins or cryptocurrencies is incorrect and can create false expectations. Furthermore, yielding a percentage of CDI depends on the conditions of each investment, and is not a promise of results.