Recovery Mode

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What is Recovery Mode?

Recovery Mode kicks in when the Total Collateral Ratio (TCR) of the system falls below 150%.

During Recovery Mode, Troves with a "Adjusted Collateral Ratio" (AICR) below the TCR of the system are eligible to be liquidated as well as those with ICR < 110%.

Stablecoin troves are still safe during recovery mode. Since this uses Adjusted Collateral Ratio, troves with purely stablecoins as collateral are not subject to these conditions due to having a higher AICR. See below for more information on adjusted safety ratios.

Moreover, the system blocks borrower transactions that would further decrease the TCR. New YUSD may only be issued by adjusting existing Troves in a way that improves their collateral ratio, or by opening a new Trove with a collateral ratio>=150%.

In general, if an existing Trove's adjustment reduces its collateral ratio, the transaction is only executed if the resulting TCR is above 150%.

What is the Adjusted Collateral Ratio?

A trove's Adjusted Individual Collateral Ratio or AICR is a ratio between collateral and debt giving additional weight to stablecoins.

ARAV = Adjusted_Safety_Ratio * Price * Collateral_Amount

AICR = ARAV / Trove_Debt

This calculation is similar to the Risk-Adjusted Value calculation except with a different ratio for each collateral. Stablecoin collaterals have an Adjusted Safety Ratio of 1.6 while other assets will have System Ratio = Safety Ratio. The idea is that we are comfortable with the full system being backed by low collateral ratio loans against yield-bearing stablecoins. But if YUSD is mostly collateralized by riskier assets, we need a higher dollar value of those assets in the system vs. YUSD issued.

What is the Total Collateral Ratio?

The Total Collateral Ratio or TCR is a number representing system safety and the value of the system collateral vs. the amount of YUSD minted against it. The system will be in "recovery mode" if the TCR is below 150%. This calculation works like the AICR calculations above.

System Collateral Value = Adjusted_Safety_Ratio * Price * Collateral_Amount

TCR = Sum_of_System_Collateral_Values_for_All_Assets / Total_YUSD_Debt

What is the purpose of Recovery Mode?

The goal of Recovery Mode is to incentivize borrowers to behave in ways that promptly raise the TCR back above 150%, and to incentivize YUSD holders to replenish the Stability Pool.

Economically, Recovery Mode is designed to encourage collateral top-ups and debt repayments, and also itself acts as a self-negating deterrent: the possibility of it occurring actually guides the system away from ever reaching it. Recovery Mode is not a desirable state for the system.

What are the fees during Recovery Mode?

While Recovery Mode has no impact on the redemption fee, the borrowing fee is set to 0% to maximally encourage borrowing (within the limits described above).

How can I make my Trove safe in Recovery Mode?

By increasing your Adjusted Collateral Ratio to 150% or greater, your Trove will be protected from liquidation. This can be done by adding collateral, repaying debt, or both.

Can I be liquidated if my adjusted collateral ratio is below 150% in Recovery Mode?

You can be liquidated in recovery mode if your Trove's adjusted collateral ratio is smaller than the TCR. In order to avoid liquidation in Normal Mode and Recovery Mode, a user should keep their trove collateral ratio (the normal one) above 110% as well as keeping their adjusted collateral ratio above 150%.

How do liquidations work in Recovery Mode?

• ICR = Individual Collateral Ratio

• MCR = Minimum Collateral Ratio

• TCR = Total Collateral Ratio

• SP = Stability Pool

Condition	Liquidation Behavior
ICR <=100%	Redistribute all debt and collateral (minus AVAX gas compensation) to active Troves.
100% < ICR < MCR & SP YUSD > Trove debt	YUSD in the Stability Pool is offset with the Trove's debt. The Trove's collateral (minus AVAX gas compensation) is shared between stability pool depositors.
100% < ICR < MCR & SP YUSD < Trove debt	The total Stability Pool YUSD is offset with an equal amount of debt from the Trove. A fraction of the Trove's collateral (equal to the ratio of its offset debt to its entire debt) is shared between depositors. The remaining debt and collateral (minus AVAX gas compensation) is redistributed to active Troves.
MCR <= ICR & AICR < TCR & SP YUSD >= Trove debt	In this case, the Stability Pool YUSD is offset with an equal amount of debt from the Trove. A fraction of collateral with dollar value equal to 1.1 * debt is shared between depositors. Nothing is redistributed to other active Troves. Since its ICR was > 1.1, the Trove has a collateral remainder, which is sent to the CollSurplusPool and is claimable by the borrower. The Trove is closed.
MCR <= ICR & AICR < 150% & SP YUSD < Trove debt	Do nothing. Because there is insufficient YUSD in the stability pool to fully offset, this trove is not liquidated
AICR >= 150%	Do nothing.

How much of a Troves collateral can be liquidated in Recovery Mode?

Liquidated collateral lost is capped at 110% of a Trove's debt. Specifically, the dollar value of the collateral sent to the stability pool is a maximum of 110% of the YUSD debt that is offset. Any remainder, i.e. the collateral above 110%, can be reclaimed by the liquidated borrower using the standard web interface.

This means that a borrower will face the same liquidation “penalty” (10%) in Recovery Mode as in Normal Mode if their Trove gets liquidated.