Risk Parameters
Each asset in the Aave protocol has specific values related to their risk, which influences how they are supplied and borrowed. The calibration of the parameters for V2 is more aggressive as the Aave ecosystem is mature with some educated users and liquidators. In addition, Gauntlet is optimising the parameters weekly based on market conditions as described in the next section.
The table below shows a summary of the latest values.
Name
Symbol
Collateral
Loan To Value
Liquidation Threshold
Liquidation Bonus
Reserve Factor
Stablecoins
Ampleforth
AMPL
no
10%
Binance USD
BUSD
no
-
-
-
10%
DAI
DAI
yes
75%
80%
5%
10%
Fei
FEI
no
20%
Frax
FRAX
no
10%
Gemini Dollars
GUSD
no
-
-
-
10%
Paxos Standard
PAX
no
10%
RAI
RAI
no
-
-
-
20%
Synthetix USD
SUSD
no
-
-
-
20%
True USD
TUSD
yes
75%
80%
5%
10%
USDC
USDC
yes
80%
85%
4%
10%
Tether
USDT
no
-
-
-
10%
Other Assets
Aave
AAVE
yes
60%
70%
7.5%
0%
Balancer
BAL
yes
65%
70%
10%
20%
Basic Attention Token
BAT
yes
70%
80%
7.5%
20%
Curve DAO
CRV
yes
45%
60%
10%
20%
DeFi Pulse Index
DPI
yes
60%
70%
10%
20%
Enjin
ENJ
yes
60%
65%
5%
20%
Ethereum
ETH
yes
82.5%
85%
5%
10%
Kyber Network
KNC
yes
60%
70%
10%
20%
yes
70%
75%
10%
20%
Decentraland
MANA
yes
65%
70%
7.5%
35%
Maker
MKR
yes
65%
70%
8%
20%
Republic Protocol
REN
yes
55%
60%
8%
20%
Ren Filecoin
RenFIL
no
-
-
-
35%
Synthetix
SNX
yes
20%
45%
7.5%
35%
Uniswap
UNI
yes
60%
70%
10%
20%
Wrapped BTC
WBTC
yes
70%
75%
7.5%
20%
Wrapped ETH
WETH
yes
80%
85%
5%
10%
Sushi Bar
XSUSHI
yes
45%
60%
10%
35%
Yearn YFI
YFI
yes
50%
65%
7.5%
20%
0x
ZRX
yes
65%
70%
7.5%
20%
The table above results from the asset risk assessment relating to security, governance and the markets. Tokens with security concerns around their smart contract cannot be considered for integration since these risks are impossible to control. Similarly, tokens with high risk exposure to single counter-parties cannot be used as collateral.
To retrieve the relevant values directly from the smart contracts, see this section of the developer docs.
Gauntlet Network has tested the model parameterisation finding a low risk of insolvency but also suggesting some minor changes to further reduce it. The details can be found in Risk Audits, Gauntlet Aave Market Risk Assessment.

# Risk Parameters Change

When market conditions change, risks change, and so we are continuously monitoring the assets integrated into the protocol which sometimes requires to quickly adapt the risk parameters. The table below tacks parameters changes which are in bold.

## Dynamic Risk Parameter by Gauntlet

AIP 29 The Aave DAO elected Gauntlet to provide dynamic risk parameters recommendations for the Aave Protocol.
Parameter
Current Value
Recommended Value
Text
Text
Text
BAT Liquidation Threshold
75%
80%
CRV Loan To Value
35%
45%
CRV Liquidation Threshold
55%
60%
ENJ Loan To Value
55%
60%
REN Loan To Value
50%
55%
SUSHI Loan To Value
30%
45%
UNI Loan To Value
55%
60%
WBTC Liquidation Bonus
7.5%
6.5%
YFI Liquidation Bonus
8%
7.5%
Asset
Reco LTV (current)
Reco LT (current)
Reco LB (current)
WETH
82.5% (80%)
CRV
35% (40%)
ENJ
55% (50%)
65% (60%)
MANA
65% (60%)
70% (65%)
UNI
50% (60%)
YFI
50% (45%)
65% (60%)
8% (10%)
ZRX
65% (60%)
XSUSHI
30% (35%)
USDC
4% (5%)

### 24/09/2021 AIP 38 Liquidation Bonus for Aave V2 Assets​

Current Liquidation_Bonus
Recommended Liquidation Bonus
WBTC (9%)
7.5%
REN (9%)
7.5%
BAT (9%)
7.5%
YFI (12.5%)
10%
MKR (10%)
8%
ZRX (8%)
7.5%
CRV (12.5%)
10%
XSUSHI (12.5%)
10%
AAVE (8%)
7.5%
MANA (8%)
7.5%
SNX (9%)
7.5%

### 14/09/2021 AIP 36 LTV and liquidations thresholds to moderate levels

Current LTV/Liq_Threshold
Moderate LTV
Moderate Liq_Threshold
USDC (80%, 85%)
82.5
85
DAI (75%, 80%)
75
80
TUSD (75%, 80%)
80
82.5
WBTC (70%, 75%)
70
75
WETH (80%, 82.5%)
80
85
REN (55%, 60%)
55
65
BAT (70%, 75%)
70
75
YFI (40%, 55%)
45
60
DPI (60%, 70%)
60
70
70
75
BAL (55%, 60%)
65
70
MKR (60%, 65%)
65
70
ZRX (60%, 65%)
60
70
UNI (60%, 65%)
60
70
KNC (60%, 65%)
60
70
CRV (40%, 55%)
40
55
XSUSHI (25%, 45%)
35
60
ENJ (55%, 60%)
50
60
AAVE (50%, 65%)
60
70
SNX (15%, 40%)
20
45

### 4/09/2021 AIP 34 Liquidations Bonus Update​

Asset
Current Liquidation Bonus
Recommended Liquidation Bonus Update
ZRX
10%
8%
WBTC
10%
9%
SNX
10%
9%
YFI
15%
12.5%
CRV
15%
12.5%
AAVE
10%
8%
REN
10%
9%
MANA
10%
8%
BAT
10%
9%
XSUSHI
15%
12.5%

## Changes from V1 to V2

Risk Parameter Change from V1 to V2

# Risk Parameters Analysis

The risk parameters allow to mitigate market risks of the currencies supported by the protocol. Each borrowing is guaranteed by a collateral that may be subject to volatility. Sufficient margin and incentives are needed for the position to remain collateralised in adverse market conditions. If the value of the collateral falls bellow a threshold, part of it is auctioned to repay part of the position and keep the ongoing borrowing collateralised.

## Collaterals

USDT, BUSD, PAX and sUSD are strongly exposed to the risk of single point of failure in their governance. Their counter-party risk is too high both in terms of centralisation and trust. For this reason, we cannot consider them to be warrant of the solvency of the protocol. On the other hand, AMPL and RAI are decentralised, though AMPL struggles with stability while RAI has little battletesting. These assets cannot be used as collaterals
Overall, stablecoins are mostly used for borrowing, while volatile assets which users are long on are mostly used as collateral. Hence, the users of the protocol still gain great benefits from the addition of these stablecoins. Their risks are mitigated by the fact they cannot be used as collateral.
Market risks can be mitigated through Aave’s risk parameters which define collateralisation and liquidation rules. These parameters are calibrated per currency to account for the specific risks identified as shown in Figure 2.

## Loan to Value

The Loan to Value (LTV) ratio defines the maximum amount of currency that can be borrowed with a specific collateral. It’s expressed in percentage: at LTV=75%, for every 1 ETH worth of collateral, borrowers will be able to borrow 0.75 ETH worth of the corresponding currency. Once a borrow is taken, the LTV evolves with market conditions.
For each wallet the maximum LTV is calculate as the weighted average of the LTVs of the collateral assets and their value:
$Max LTV = \frac{ \sum{Collateral_i \: in \: ETH \: \times \: LTV_i}}{Total \: Collateral \: in \: ETH \:}$

## Liquidation Threshold

The liquidation threshold is the percentage at which a position is defined as undercollateralised. For example, a Liquidation threshold of 80% means that if the value rises above 80% of the collateral, the position is undercollateralised and could be liquidated.
The delta between the Loan-To-Value and the Liquidation Threshold is a safety cushion for borrowers.
For each wallet the Liquidation Threshold is calculate as the weighted average of the Liquidation Thresholds of the collateral assets and their value:
$Liquidation \: Threshold= \frac{ \sum{Collateral_i \: in \: ETH \: \times \: Liquidation \: Threshold_i}}{Total \: Collateral \: in \: ETH \:}$

## Liquidation Bonus

Bonus on the price of assets of the collateral when liquidators purchase it as part of the liquidation of a loan that has passed the liquidation threshold.

## Health Factor

For each wallet, these risks parameters enable the calculation of the health factor:
$H_f = \frac{ \sum{Collateral_i \: in \: ETH \: \times \: Liquidation \: Threshold_i}}{Total \: Borrows \: in \: ETH}$
When
$H_f < 1$
the position may be liquidated to maintain solvency as described in the diagram below.
Risk Parameters Safeguard Solvency

## Reserve Factor

The reserve factor allocates a share of the protocol's interests to a collector contract as reserve for the ecosystem. This reserve is new to V2, used to sustain the DAO and pay protocol contributors. It is made out of various assets including AAVE.
Aave's solvency risk is covered by the Safety Module, with the incentives coming from the ecosystem reserve. As such, the Reserve Factor is also a risk premium and so it is calibrated based on the overall risk of the asset. Stablecoins are the less risky assets with lower reserve factor while volatile assets hold more risk with a higher factor.
The collector contract can be found at 0x464c71f6c2f760dda6093dcb91c24c39e5d6e18c.

## From Risks to Risk Parameters

Market risks have the most direct impact on the risk parameters:

### Liquidity

The liquidity is based on the volume on the markets, which is key for the liquidation process. This can be mitigated through the liquidation parameters: the lower the liquidity, the higher the incentives.

### Volatility

The volatility of price can negatively affect the collateral which safeguards the solvency of the protocol and must cover the liabilities. The risk of the collateral falling below the borrowed amounts can be mitigated through the level of coverage required, the Loan-To-Value. It also affects the liquidation process as the margin for liquidators needs to allow for profit.
The less volatile currencies are the stablecoins followed by ETH, they have the highest LTV at 75%, and the highest liquidation threshold at 80%.
The most volatile currencies REP and LEND have the lowest LTV at 35% and 40%. The liquidations thresholds are set at 65% to protect our users from a sharp drop in price which could lead to undercollaterisation followed by liquidation.

### Market Capitalisation

The market capitalisation represents the size of the market, which is important when it comes to liquidating collateral. This can be mitigated through the liquidation parameters: the smaller the market cap, the higher the incentives.

### Overall Risk

The overall risk rating is used to calibrate the Reserve Factor with factors ranging from 10% for the less risky assets to 35% for the riskiest.