Lower the aDOT borrow rate curve
Summary
This referendum switches the DOT (aDOT) money-market reserve to a new interest rate strategy. The base rate drops from 1% to 0% and the rate at the 85% optimal utilization point drops from 4.5% to 2.75%. The rate at 100% utilization stays at 49.5%.
Motivation
The key driver behind this is the recent further reduction in DOT staking rewards - this strategy change aims to make GDOT/vDOT looping profitable at higher utilisation. DOT borrowing on Hydration currently sits at around 40% utilization. The existing curve charges 1% before any DOT is borrowed and 2.66% at today's utilization. A flatter curve below the kink makes aDOT cheaper to borrow against the same collateral while keeping the steep slope above 85% that protects suppliers' ability to withdraw.
Parameters
| Parameter |
Current |
Proposed |
| Base variable borrow rate |
1.00% |
0.00% |
| Slope 1 (0% to 85% utilization) |
3.50% |
2.75% |
| Slope 2 (85% to 100% utilization) |
45.00% |
46.75% |
| Optimal utilization |
85% |
85% |
| Borrow rate at 85% |
4.50% |
2.75% |
| Borrow rate at 100% |
49.50% |
49.50% |
At the current utilization of 40.35% the borrow APR moves from 2.66% to 1.31% and the aDOT supply APR from 0.97% to 0.47%.
Technical details
Aave v3 interest rate strategies are immutable contracts, so the change requires a new strategy deployment and a governance call pointing the reserve at it. The new strategy is deployed at 0xD3798D35EE1C552bB7C5Ee6641118cf800Ea565A and its parameters have been verified on chain.
The call dispatches PoolConfigurator.setReserveInterestRateStrategyAddress for the DOT reserve through the Aave manager. It has been dry-run on a chopsticks fork of mainnet, where it executed successfully and emitted the expected ReserveInterestRateStrategyChanged event.
Preimage hash: 0x82ef39f8c99ff98145d7fe1fe94f45b67b2b68c03269f91f2f722a3ce09383c0
Source: https://github.com/galacticcouncil/money-market/compare/hydration...feat/dot-rate-strategy