> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tangent.finance/llms.txt
> Use this file to discover all available pages before exploring further.
# FIR markets
## General concepts[](#general-concepts "Direct link to General concepts")
On **FIR** markets, borrowers can mint `USG` against productive collateral, such as [Curve Finance](https://www.curve.finance/dex/ethereum/pools/) LP tokens or [Pendle](https://www.pendle.finance/) PTs.
On these markets, a fixed interest rate is charged immediately, and is materialized for borrowers by an always-increasing debt. If the collateral produces *liquid rewards*, 90% of these rewards are streamed back to borrowers, as the protocol applies a 10% fee. No progressive rewards deduction is applied on **FIR** markets.
Unlike in **HEC** and **LEC** markets, the interest rate in **FIR** markets doesn't fluctuate with the price of `USG`; it remains constant.
The fixed interest rate can vary across **FIR** markets, depending on the collateral's nature. Additionally, following a DAO vote, the rate can be adjusted, and an **FIR** market can become an **HEC** or **LEC** market (and vice versa).
Following a significant and sustained depeg of `USG`, an **FIR** market will be converted into an **HEC** or **LEC** market to encourage borrowers to repay. It is your responsibility to monitor your loan.
To summarize, on **FIR** markets:
* Interest starts accruing immediately when a loan is created;
* If the collateral produces *liquid rewards*, 90% of these rewards are streamed back to borrowers;
* The interest rate is fixed;
* An **FIR** market will be converted into an **HEC** or **LEC** market if `USG` depegs significantly.
## Financial flows[](#financial-flows "Direct link to Financial flows")
The figure below shows the financial flows on **FIR** markets.
