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7. MARKETABLE SECURITIES (Details) - BRL (R$) R$ in Millions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Disclosure of Investment Securities [line items] |  |  |  |
Current investments |  | R$ 3,360 | R$ 740 | [1]
Non-current investments |  | 765 | 13 | [1]
Investments |  | 4,125 | 753 |
Bank deposit certificates (CDBs) [member] |  |  |  |
Disclosure of Investment Securities [line items] |  |  |  |
Current investments | [2] | 545 |  |
Financial Notes Banks [member] |  |  |  |
Disclosure of Investment Securities [line items] |  |  |  |
Current investments | [3] | 2,074 | 645 |
Non-current investments |  | 730 | 11 |
Marketable securities - treasury financial notes [member] |  |  |  |
Disclosure of Investment Securities [line items] |  |  |  |
Current investments | [4] | 731 | 94 |
Debentures [member] |  |  |  |
Disclosure of Investment Securities [line items] |  |  |  |
Current investments | [5] |  |  |
Non-current investments | [6] | 25 | 2 |
Other Investment [member] |  |  |  |
Disclosure of Investment Securities [line items] |  |  |  |
Current investments |  | 10 | R$ 1 |
Non-current investments |  | R$ 10 |  |
[1] | See note 2.8.
[2] | Bank Deposit Certificates (CBDs), accrued interest at 106% a 110% of the CDI Rate (Interbank deposit rates) published by the Custody and Settlement Chamber (Cetip) in 2020.
[3] | Bank Financial Notes (Letras Financeiras, or LFs) are fixed-rate fixed-income securities, issued by banks and that accrued interest a percentage of the CDI rate published by Cetip. The LFs had remuneration rates varying between 99.5% and 130% of the CDI rate in 2020 (101.95% and 113% in 2019 and 102% to 111.25% in 2018).
[4] | Treasury Financial Notes (LFTs) are fixed-rate securities, their yield follows the daily changes in the Selic rate between the date of purchase and the date of maturity.
[5] | Debentures are medium and long term debt securities, which give their holders a right of credit against the issuing company. The debentures have remuneration varying from 108.25% to 113% of the CDI Rate in 2019 (104.25% to 151% of CDI in 2018 and 104.25% to 161.54% of CDI in 2017).
[6] | Debentures are medium and long term debt securities, which give their holders a right of credit against the issuing company. The debentures have remuneration varying from TR+1% to 109% of the CDI Rate in 2020 (108.25% to 113% of CDI in 2019 and 104.25% to 151% of CDI in 2018).

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