Is Brazil's 'deposit' interest rate 15% per year? Understanding money news through interest rates, prices, and exchange rates
If you deposit money, it will increase by 15% per year.
I think many people would be interested if they heard that.
The Nikkei newspaper reported on September 22, 2026, that individual funds are flowing into a financial product in Brazil called a ‘CDB’ that offers a yield of around 15% per year. The spread of social media and digital banks is also said to be boosting participation in investment.Nikkei newspaper article
However, this 15% is not an interest rate applied to all deposits in Brazil. Also, it does not mean that money held in Japanese yen will simply increase by 15%.
This news becomes much easier to understand if you think about interest rates, prices, and exchange rates separately.
First, what is a CDB?
It is introduced in Japanese as a ‘negotiable certificate of deposit,’ but to grasp how it works, it is best to think of it as a product where you lend money to a bank under certain conditions and receive interest in return.
According to the Brazilian exchange B3, a CDB is one of the ways banks raise funds. The term and the method of calculating interest are determined by the contract, and some products can be cashed in daily. In other words, even with the same CDB, the yield and the conditions for withdrawing money differ.B3’s explanation of CDB
When a high interest rate catches your eye, you also need to look at ‘when the money can be used’.
And, essential to understanding bank interest rates is the central bank’s ‘policy interest rate’.
The policy interest rate is a benchmark that influences various interest rates in the country. When the central bank raises interest rates, the burden of borrowing money increases, which works to curb corporate investment and household consumption. By doing so, it attempts to stabilize rising prices.Explanation of Brazil’s central bank monetary policy
High interest rates have both the aspect of increasing the income of those who invest money and the aspect of increasing the burden on those who borrow money.
When you hear about a ‘country with high interest rates,’ looking at both sides makes the economic picture a bit more three-dimensional.
Another thing to consider along with the interest received is prices.
For example, even if your account balance increases, if food, rent, and other costs rise, what you can buy will not increase at the same rate.
What you should look at is not just the amount displayed in the account, but how much you can buy with that money. This is what it means to look at money while considering prices.
Furthermore, for those of us living in yen, ‘exchange rates’ are involved.
Here, I will perform a hypothetical calculation to understand the mechanism. This does not show actual product conditions or current exchange rates, and is an example that does not consider taxes or fees.
First, suppose you exchanged 300,000 yen for 10,000 reais at a rate of 1 real = 30 yen.
If that 10,000 reais increases by 15% in one year, it becomes 11,500 reais.
However, the amount when converted back to yen will change depending on the exchange rate at that time.
Amount converted back to yen after one year: 1 real = 30 yen: 345,000 yen; 1 real = 27 yen: 310,500 yen; 1 real = 24 yen: 276,000 yen
The money in reais has increased by 15% in all cases.
Even so, if the value of 1 real in yen drops from 30 yen to 24 yen, the amount converted back to yen will fall below the initial 300,000 yen.
You need to look at the yield in the local currency and the profit or loss in the currency you use separately.
Regarding protection in the event of a bank failure, it is also essential to check the conditions.
Brazil’s guarantee agency, the FGC, includes CDBs in its scope of protection. However, there are caps, such as up to 250,000 reais per person per financial institution or financial group, and there is also a total limit of 1 million reais over four years for guarantees against multiple failures.FGC Guarantee System
Even with such protection against bank failures, the decrease in the yen-converted amount due to exchange rates, as in the example above, must be considered separately.
Looking at it this far, it is clear that there are several conditions to check around the 15% figure.
On the other hand, this news also highlights a change in that the gateway to financial products is expanding.
According to a survey by the Brazilian financial market association ANBIMA, among those investing in financial products, the proportion using private bonds such as CDBs and corporate bonds increased from 8% in 2021 to 20% in 2025. While this is not a figure for CDBs alone, it suggests that the range of investment options is expanding.ANBIMA ‘Brazil Investor Survey’ 9th Edition, page 29
The social media and investment apps introduced in the Nikkei article are also supporting this change. Even without going to a bank counter, people can now have opportunities to learn about and compare products.
What I want to consider from this news is the point that there is still a gap between the ease of participating in investments and the widespread reach of their benefits.
Even if information reaches people, if they are struggling to make ends meet daily, it is difficult to set aside money for investment. Conversely, those with substantial assets can receive more interest even with the same yield.
That is why I believe it is important to both expand financial knowledge and create an environment that allows for household financial flexibility.
And what we can take away from this news is a perspective on financial products.
When you see an interest rate, also check the currency, when you can withdraw, taxes and fees, and the scope of protection.
That extra bit of effort turns an attractive number into information that is meaningful to you.
When you deposit money, what conditions other than the interest rate do you value?