DeFi oracles [DRAFT for review]

	A	B	C
1	Name	Oracle Method [DRAFT for review]	Source

2		Update on 3/11/20 - Please reference the GitHub list going forward so others can contribute and it's easier to keep up to date https://github.com/linda-xie/defi-oracles
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4	Aave	Chainlink for 16 cryptocurrency price feeds	https://medium.com/aave/the-aave-oracle-network-powered-by-chainlink-is-now-live-45bb8a5a8c4e
5	Augur	After a market enters reporting, an Initial Reporter (typically the market creator), selects which outcome occurred. This becomes the “Tentative Winning Outcome.” Users can dispute the Tentative Winning Outcome by staking REP on an alternative outcome that they believe to be correct. An alternative outcome requires a specified threshold of REP, which is called the Dispute Bond, to be staked on it in order to become the new Tentative Winning Outcome. In v2, if you stake REP in favor of an outcome that the market ends up resolving to, you receive a 40% ROI on your staked REP (except in the case of an usued pre-stake or initial reporting). If you stake on an outcome that the market does not end up resolving to, you lose your entire stake. With each successive dispute round, a higher Dispute Bond is needed to shift the Tentative Winning Outcome. A user may contribute the full Dispute Bond or fill it partially as part of a crowd-sourced fill along with other users.	https://www.augur.net/blog/v2-resolution/
6	bZx	The current bZx oracle solution for 60+ tokens is supported by the KyberNetwork. bZx will incorporate Chainlink’s functionality to build a separate oracle solution on top of the base bZx protocol.	https://medium.com/bzxnetwork/bzx-teams-up-with-chainlink-5b9649e8c241
7	Compound	The price of BAT, REP, ZRX, and WBTC are a median of prices from Coinbase Pro, Bittrex, Poloniex, and Binance, denominated in Ether, and posted on-chain after a 1% deviation in an asset’s median price. For security, price changes are limited (at the protocol level) to 10% per hour, unless a manual approval is provided by a second, offline address. DAI, SAI, and USDC are based on Maker’s ETH/USD price feed. Compound is developing an advanced price feed, the Open Oracle System, to create a transparent, decentralized, resilient, and tamper-proof price feed.	https://medium.com/compound-finance/faq-1a2636713b69 https://medium.com/compound-finance/announcing-compound-open-oracle-development-cff36f06aad3
8	DDEX	Uses on-chain price oracles to determine real-time USD prices. These price oracles are different for each market (example: the ETH-DAI market will use the MakerDAO ETH-USD price oracle), chosen based on stability. They have several safety mechanisms built into the price determination process to guard against oracle failures: both on a contract level and algorithmically	https://medium.com/hydro-protocol/ddex-faq-margin-trading-bd4b32beb9f
9	dYdX	Prices are fed to the dYdX smart contracts through price oracles that run on Ethereum. dYdX uses different price oracles for different assets. For ETH, dYdX uses the MakerDAO ETH-USD V1 Oracle that is used by MakerDAO for their stablecoin SAI, and relies on a distributed network of reporters that report the price of ETH in USD. For DAI, dYdX uses our own price oracle which calculates the USD price of DAI using a combination of Oasis Trade's on-chain orderbook, Uniswap, and the MakerDAO ETH-USD oracle. The oracle also has several protections against price manipulation on eth2dai and Uniswap. For USDC, dYdX uses a price of $1 as USDC is exchangeable 1:1 with USD on Coinbase.	https://help.dydx.exchange/en/articles/2953486-where-does-price-information-come-from
10	MakerDAO	The reference price (ETHUSD) for the Maker system is provided via an oracle (the medianizer), which collates price data from a number of external price feeds. https://makerdao.com/en/feeds/ Independent price feed operators constantly monitor the reference price across a number of external sources and will submit updates to the blockchain when: 1. Source price differs to the most recently submitted price by more than the defined amount (currently 1%) 2. Last price update was more than 6 hours ago. Price updates are written to the blockchain via price feed contracts which are deployed and owned by feed operators. Price feed contracts which have been whitelisted by the medianizer are able to forward their prices for inclusion in the medianized price. The medianizer is the smart contract which provides Makers trusted reference price. It maintains a whitelist of price feed contracts which are allowed to post price updates and a record of recent prices supplied by each address. Every time a new price update is received the median of all feed prices is re-computed and the medianized value is updated. Permissions: The adding and removal of whitelisted price feed addresses is controlled via governance, as is the setting of the min parameter - the minimum number of valid feeds required in order for the medianized value to be considered valid. v2 introduces several new proposals: 1. Add a set of DeFi partners as Feeds 2. An Oracle Team Mandate to create an Oracle Team role. The mandate will empower MKR Governance to appoint Oracle Team(s) to perform certain tasks on their behalf. 3. MKR Governors’ control of the Oracles infrastructure be formalized via an Oracle Governance Framework. 4. New incentive structure for Oracles.	https://developer.makerdao.com/feeds/ https://blog.makerdao.com/introducing-oracles-v2-and-defi-feeds/
11	Nexus Mutual	Members will act as judges, with each claim subject to a yes/no vote by members who have chosen to stake a portion of their tokens to act as Claims Assessors. The Claims Assessors earn rewards for voting with the consensus outcome. If anyone is deemed to have voted fraudulently, their stake may be burned via the Governance process. Nexus Mutual is using Chainlink’s price reference data contracts for valuations of the multi-currency capital pool. Nexual Mutual performs daily on-chain updates and rebalances of its minimum capital requirement (MCR) by consistently recalculating the value of each capital asset (currently ETH and DAI) in the multi-currency pool using Chainlink’s Price Reference Data Contracts.	https://nexusmutual.gitbook.io/docs/faq https://medium.com/nexus-mutual/nexus-mutual-is-now-using-chainlinks-price-reference-data-contracts-for-decentralized-valuations-6a62c5d4e030
12	Nuo	For any currency pair, Nuo uses best price provided by decentralised exchanges (Pd) and hard-fences it using volume weighted average price aggregated over price feeds from centralised exchanges (Pc). Currently Nuo uses Kyber and Uniswap as decentralised partner exchanges. Among centralised exchanges, Nuo tracks price and volume across all major cexes with >50 total cexes added already. At any time, for any currency pair, Pd = Best Price across partner decentralised exchanges Pc = TimeDecaySum( Sum( VolumeOfCex * PriceByCex ) / TotalVolumeAcrossAllCexes ) VolumeOfCex, PriceByCex and TotalVolumeAcrossAllCexes use clustering techniques to remove anomalies in price/volume and ignore exchanges with poor pricing. TimeDecaySum is built to reduce effect of a high volume exchange going offline for a while by reducing the weight of the price obtained from a cex based on the duration when the last trade was recorded from it. For any currency pair, Nuo hard-fencing ensures the following holds true: lower_fence * Pc < Pd < upper_fence * Pc Currently, fencing percentage is placed at 10% system-wide. Hence, lower_fence = 0.9 and upper_fence = 1.1. We can expect a tighter fence as dexes get more efficient and liquid in future At any point in time, if the above condition does not hold true, the exchange market is paused and resumed again when the condition becomes true. This is done to prevent any unwanted liquidations from happening on the platform due to price manipulations or flash crashes across our partner dexes. There are plans to potentially integrate Chainlink in a future version.	https://nuo.drift.help/article/how-does-nuo's-price-feed-work/ https://twitter.com/getnuo/status/1230221716934340608
13	Synthetix	Chainlink for FX and commodity price feeds with plan to integrate cryptocurrencies and indices in the future. Other price feeds are determined by an oracle that pushes price feeds on-chain using an algorithm with a variety of sources to form an aggregate value for each asset. It is currently operated by the Synthetix team https://etherscan.io/address/0x565C9EB432f4AE9633e50e1213AB4f23D8f31f54	https://blog.synthetix.io/chainlink-decentralizes-first-wave-of-synthetix-price-feeds/ https://www.synthetix.io/uploads/synthetix_litepaper.pdf
14	Token Sets	On-chain prices used by their smart contracts are sourced from MakerDAO's oracles (BTC and ETH), and prices for buying and selling are sourced from DEXs that provide liquidity to Set Protocol. They use Chainlink's LINK/USD oracle to power the LINK sets and also have their own on-chain moving average and RSI oracles. Each Smart Contract Managed Rebalancing Set system is made of three distinct parts: 1) Manager Contract that generates rebalancing proposals based off on-chain data, 2) Oracles that are used to provide data to the Manager Contract and, 3) the Rebalancing Set Token that stores state (balances, allocations, etc.) regarding the strategy.	https://www.tokensets.com/ https://medium.com/set-protocol/introducing-the-link-rsi-set-on-tokensets-fe3b4fcacf94 https://github.com/SetProtocol/set-protocol-strategies/wiki
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