On behalf of Getty Hill & Eddy Lee, Polychain is submitting their proposal to add AAVE, SUSHI, and YFI to Compound. Each of these coins are blue chip tokens and widely supported in the industry. 

[Forum thread](https://www.comp.xyz/t/add-markets-mkr-aave-sushi-yfi/)

[Simulation](https://github.com/gfx-labs/compound-protocol/tree/elee/spec/sim)

[cSUSHI](https://etherscan.io/address/0x4B0181102A0112A2ef11AbEE5563bb4a3176c9d7)
[cAAVE](https://etherscan.io/address/0xe65cdB6479BaC1e22340E4E755fAE7E509EcD06c)
[cYFI](https://etherscan.io/address/0x80a2AE356fc9ef4305676f7a3E2Ed04e12C33946)

Proposal calls:
- Add Comptroller support for cSUSHI
- Add Comptroller support for cAAVE
- Add Comptroller support for cYFI
- Set the reserve factor to 25% for each market (standard parameter)
- Add a borrow cap of 60k for AAVE (recommend by the AAVE team)
- Add a borrow cap of 1500 for YFI

Add AAVE, SUSHI, YFI

On behalf of Getty Hill & Eddy Lee, I am submitting their proposal to add MKR to Compound. MKR is the oldest running DeFi project and has been considered for addition since Compound V1. 

[Forum thread](https://www.comp.xyz/t/add-markets-mkr-aave-sushi-yfi/)

[Simulation](https://github.com/gfx-labs/compound-protocol/tree/elee/spec/sim)

[cMKR](https://etherscan.io/address/0x95b4eF2869eBD94BEb4eEE400a99824BF5DC325b)

[New oracle](https://etherscan.io/address/0x6D2299C48a8dD07a872FDd0F8233924872Ad1071) with MKR, AAVE, SUSHI, and YFI prices. 
Chainlink has initiated the ownership transfer of the UAV to the community multisig. 

This proposal initiates cMKR with a 25,000 MKR borrow cap, which reduces the risk of governance attacks and the systemic risk of DeFi.

Add MKR Support

Governance Bravo presents the ability to update governance parameters. Here, we alter the amount of COMP needed by a CAP or COMP address to push a governance proposal to a vote.

While this 65k threshold only enables 1 additional EOA to propose, it makes the CAP process considerably easier to navigate for community contributors. Over time, this threshold may be reduced further, but this is a conservative & meaningful step in the right direction.

This proposal stems from discussion started by arr00: https://www.comp.xyz/t/lower-proposal-threshold/1659

Lower Proposal Threshold to 65,000 COMP

### Background
Over the last 6-months, Getty Hill has worked to improve Compound’s oracle system; he coordinated [Proposal 47](https://compound.finance/governance/proposals/47), a months-long effort to harden the Compound price feed, which met the highest possible standard demanded by the Compound community.
### Contributor Grant
Getty requested an streaming grant for his prior and future efforts to coordinate oracle development;
> While the major update has been made, more work is still needed. We still need to transition the Uniswap anchor from v2 to v3, support additional markets, [ongoing monitoring](http://defialerts.io/oracle), and further research the system’s efficiency. The recent milestone is the beginning of a more vigilant and efficient Compound.
> I am requesting a 0.000214 [Contributor Comp Speed grant](https://compound.finance/governance/proposals/30) from the protocol. Over the last 6-months, I acted as the project manager for the oracle improvement. I researched a myriad of options, worked closely with the Chainlink team, managed community feedback and input, championed the project, and most importantly, got it through governance. The ongoing contributor grant will be for the work I have done to get the oracle improvement in place and to manage it going forward.
This Contributor Grant will be used to carry on the work of improving the price feed, and represents the first streaming COMP grant. The grant runs in perpetuity until modified by governance.
[Discussion](https://www.comp.xyz/t/oracle-contributor/1887)

Contributor Grant: Getty Hill

This proposal is a patch, developed by Compound Labs, which updates the Comptroller implementation contract.

### Changelog

The `claimComp` function has been optimized to significantly reduce the gas cost of claiming COMP across multiple markets at once, by combining all rewards into a single transfer.

Markets with a 0% Collateral Factor, 100% Reserve Factor, and Borrowing Paused are inferred to be *deprecated* by the Comptroller, and allowed to be completely liquidated. This allows the closure of all outstanding borrows and the removal of reserves in deprecated markets including SAI, REP, and future migrations.

### Development

This patch was developed publicly, coupled with completed scenario analysis. In addition to the Compound Labs bug bounty program, a secondary bug bounty was offered through [Immunefi](https://immunefi.com/bounty/compound/).

[Discussion](https://www.comp.xyz/t/safety-and-gas-patches/1723)

Close Deprecated Markets, Gas Savings

This proposal is a patch, developed by Compound Labs, which updates the base cToken implementation contract, and adopts it across all upgradable markets.

### Changelog
The `seize` function has been modified to transfer 2.8% of a liquidation to cToken reserves, reducing the risk of cascading liquidations that could render the protocol insolvent. With each liquidation, the protocol’s ability to recover (or utilize reserves) increases.

Given the proliferation of COMP-like governance tokens, the `delegate` function has been merged into the base cToken implementation.

### Adoption
The seven upgradable cTokens, deployed starting 18 months ago, currently rely on five different cToken implementation contracts, many of which lack the most modern features.

This proposal unifies all upgradable cTokens with a single implementation, which reduces the surface area of technical debt, and slightly reduces gas costs.

### Development
This patch was developed publicly, coupled with completed scenario analysis. In addition to the Compound Labs bug bounty program, a secondary bug bounty was offered through [Immunefi](https://immunefi.com/bounty/compound/).

During the review period for [Proposal 048](https://compound.finance/governance/proposals/48), community member pyggie identified potential improvements to the cToken event logs and public interface; these have been included in this proposal, alongside a bounty of 30 COMP for their efforts.

[Discussion](https://www.comp.xyz/t/safety-and-gas-patches/1723)

Update and Standardize cToken Implementation

This proposal is a patch, developed by Compound Labs, which updates the base cToken implementation contract and adopts it across all upgradable markets.

### Changelog
The `seize` function has been modified to transfer 2.8% of a liquidation to cToken reserves, reducing the risk of cascading liquidations that could render the protocol insolvent. With each liquidation, the protocol's ability to recover (or utilize reserves) increases.

Given the proliferation of COMP-like governance tokens, the `delegate` function has been merged into the base cToken implementation.

### Adoption
The seven upgradable cTokens, deployed starting 18 months ago, currently rely on five different cToken implementation contracts, many of which lack the most modern features.

This proposal unifies all upgradable cTokens with a single implementation, which reduces the surface area of technical debt, and slightly reduces gas costs.

### Development
This patch was developed publicly, coupled with completed scenario analysis. In addition to the Compound Labs bug bounty program, a secondary bug bounty was offered through [Immunefi](https://immunefi.com/bounty/compound/).

[Discussion](https://www.comp.xyz/t/safety-and-gas-patches/1723)

## Introduction

This proposal will change the current oracle system from using Coinbase as the primary reporter of prices to Chainlink [Price Feeds](http://data.chain.link). Uniswap v2 is still used as an anchor (circuit breaker) and the anchor deviation window will change from 20% to 15%. As a precaution, the community multisig has the ability to engage a failover that will switch a market’s primary oracle from the current Price Feeds to Uniswap v2.

### Proposal Call

Change the Comptroller oracle from [0x4007B71e01424b2314c020fB0344b03A7C499E1A](https://etherscan.io/address/0x4007B71e01424b2314c020fB0344b03A7C499E1A) to [0x841616a5CBA946CF415Efe8a326A621A794D0f97](https://etherscan.io/address/0x841616a5CBA946CF415Efe8a326A621A794D0f97)

### Oracle Update Details

Each asset supported on the Compound market has a corresponding USD-paired price feed reference contract and a validatorProxy contract (which allows for the UniswapAnchorView (UAV) oracle contract to be updated by the community as new markets are added). When the reference contract of a Price Feed is updated by a decentralized network of oracle nodes with a new aggregated price value, the transmitter of that data also calls the validate() function on the market’s validatorProxy contract. When this function is called, the validatorProxy calls validate() on the UAV, which queries Uniswap v2 to check if the new price is within the Uniswap v2 TWAP anchor. If valid, the UAV is updated with the asset’s price. If invalid, the price data is not stored. Additional details on this process can be found in this comment [here](https://www.comp.xyz/t/oracle-infrastructure-chainlink-proposal/1272/55) on the Compound forum.

[Here](https://aws1.discourse-cdn.com/standard17/uploads/compoundcommunity/original/1X/7033ce2e313f56c40441ba6dd9d900b0c2b244a7.png) is a visual example of how BAT/USD price feed is used, though this flow is the same for all asset markets.

The frequency of updates for each price feed depends on two triggers:

* Deviation threshold - when the off-chain price of an asset is witnessed to have moved more than x% of the previously reported price, an on-chain update is initiated.

* Heartbeat threshold - If x minutes have passed without an update, a new on-chain update is initiated.

More information can be found on [data.chain.link](http://data.chain.link/). Example: [ETH / USD](https://data.chain.link/eth-usd).

Price update events can be witnessed on the[ Etherscan events tab](https://etherscan.io/address/0x841616a5CBA946CF415Efe8a326A621A794D0f97#events).

The UniswapAnchorView token configuration has two additional fields: reporter & reporterMultiplier.

* reporter: The address that submits prices for a particular cToken. This is always a ValidatorProxy contract that is always called by a price feed reference contract for each relevant price update posted by oracle nodes. In this case, 0xeBa6F33730B9751a8BA0b18d9C256093E82f6bC2 is the reporter of the price of BAT.

* reporterMultiplier: Used to transform the price reported by the price feeds to the correct base unit that the UniswapAnchoredView expects. This is required because the price feeds report prices with different decimal placement than the UniswapAnchoredView.

Audit report: Trail of Bits was commissioned for audit of the contracts.[ToB Audit report](https://drive.google.com/file/d/1TsOXhBLenStjdd2mxF1Sfmmh_Na9X527/view?usp=sharing)

Forum discussion and additional details: [Oracle Infrastructure: Chainlink Proposal](https://www.comp.xyz/t/oracle-infrastructure-chainlink-proposal/1272)

#### Why

In late January I wrote on the [forum](https://www.comp.xyz/t/building-a-medianizer/1031) “Compound NEEDS to improve the current oracle infrastructure as a matter of safety and growth. I think it is evident to users that the current solution is not ideal and not close to ideal. The event that occurred in November with Dai liquidations was preventable….In addition to preventing the November event from transpiring again, I think it is also in the protocol’s best interest to improve the oracle situation so Compound can safely support more assets.”

Five months, two forum threads, 114 forum replies, numerous calls, countless messages, and finally, we have a robust solution to improve the oracle system. This has been a long process, going over and re-reviewing many nuanced details with the community. Building in public is not always easy, but it was an insightful process and I am excited to see more assets on Compound. I look forward to continuing to improve the oracle system as the crypto landscape changes.

Oracle Improvement

LINK is a widely distributed token, with significant liquidity both on and off-chain. As a new market, it will be introduced with the following conservative market parameters: 
 - Collateral Factor: 0%
 - Reserve Factor: 25%
 - COMP Speed: 0.0014625 (also set for UNI, BAT, ZRX)
 - Interest Rate Model (JumpRateModelV2)
 - 2% APY borrow base rate
 - 20% APY borrow rate at kink
 - Kink at 80% utilization
 - 100% APY borrow rate at 100% utilization

A 0% collateral factor provides a “no risk” approach to adding the new asset, and allows the protocol to test if the interest rate model and other parameters are a proper fit. Once the market develops there can be an immediate follow-up proposal to increase the collateral factor based on market performance, stress tests etc.

The Reserve Factor, COMP Speed, and Interest Rate Models were chosen based off the parameters for similar assets (UNI, ZRX, and BAT)

#### Oracle
The current oracle and TUSD proposal's new oracle is compatible with LINK there is no change needed.

#### cLINK Contract
The cLINK contract is based on the most recently deployed cToken (cWBTC2) implementation, which includes a sweepToken enhancement for governance to collect accidentally sent tokens received by the proxy contract.

#### Special Thanks

Special thanks goes out to MasterofNonce for writing the CAP description; Arr00 for helping write simulations; mistertom, jmo, blck, and rleshner for helping decide the parameter proposals; and the community in general for the support and TRiLeZ to organize and deploy the necessery contract and the whole proposal.

#### References
 - [cLINK contract](https://etherscan.io/address/0xface851a4921ce59e912d19329929ce6da6eb0c7#code)
 - [Forums discussion](https://www.comp.xyz/t/add-market-link/1516)
 - [Integration scenario](https://github.com/TRiLeZ/compound-protocol/blob/clink-integration/spec/sim/0010-clink-integration/hypothetical_clink_integration.scen)
 - [Updated mainnet.json](https://github.com/TRiLeZ/compound-protocol/blob/clink-integration/networks/mainnet.json)
 - [Updated token deploy script used](https://github.com/TRiLeZ/compound-protocol/blob/update-deploy-token/script/saddle/deployToken.js)

Add LINK Support

This proposal adds [TrueUSD](https://etherscan.io/token/0x0000000000085d4780B73119b644AE5ecd22b376) as a supported asset.  
 
TUSD is a 1:1 US dollar backed stablecoin. TUSD is the only stablecoin that has [real-time, 24/7 attestations](https://real-time-attest.trustexplorer.io/trusttoken) from Armanino, a top US accounting firm, providing assurance that the token is fully collateralized by US Dollars. 
 
## Market Parameters 
This proposal sets TUSD with a collateral factor of 0%, reserve factor of 7.5%, and unlimited borrow cap. These parameters follow the values set by USDT, with 0% collateral factor. The collateral factor can be proposed to be higher with a future proposal. 
 
 This proposal updates the Compound price feed to peg TUSD to $1, similarly to USDC. By using a peg, weakness in the underlying asset will not change collateral requirements for users borrowing TUSD.
 
[The interest rate model](https://etherscan.io/address/0xfb564da37b41b2f6b6edcc3e56fbf523bd9f2012) for TrueUSD relies on the same model as cUSDT and cDAI, JumpRateModelV2. 
 
## Contracts 
cTUSD is an upgradeable cToken contract that has been modified to accommodate potential transfer fees in the underlying token. 
 
The cToken contract has been reviewed by OpenZeppelin and the Compound team. The cTUSD contract has been reviewed by the TrustToken and Ethworks teams. 
 
The case for why TUSD benefits compound has been discussed by the [compound community here](https://www.comp.xyz/t/trueusd-listing-proposal-stay-tuned/1490)

Vote By Signature

54

Total Proposals

Recent Proposals

Add AAVE, SUSHI, YFI

Add MKR Support

Lower Proposal Threshold to 65,000 COMP

Contributor Grant: Getty Hill

Close Deprecated Markets, Gas Savings

Update and Standardize cToken Implementation

Update and Standardize cToken Implementation

Oracle Improvement

Add LINK Support

Add TUSD Support

Public API