On Thursday, November 26th, the price of the Dai stablecoin (ordinarily ~$1 USD) exploded up to $1.30 on Coinbase as traders tried to snag up funds en masse to pay back, and thus keep afloat, their DeFi lending positions.
Yet this Dai price spike, combined with an acutely falling ETH price, pushed some Dai positions on DeFi lending protocol Compound into being undercollateralized and thus capable of being liquidated.
This dynamic played out because Compound’s Dai markets centrally rely on Coinbase’s Dai price feed, which skewed upward compared to other exchanges during this episode because many of Coinbase’s users were uniquely piling into Dai all at once.
This sequence of events led to more than $100 million worth of liquidations on Compound, which in turn led to considerable debate around the Ethereum ecosystem as to whether Compound messed up by overly relying on a single oracle of if the whole incident was just an unfortunate possibility panning out in the young DeFi arena.
Manipulation or Not?
In the wake of the Compound liquidations, people quickly started started positing that the underlying Dai price spike on Coinbase was the result of manipulation, i.e. a price oracle manipulation attack.
However, it’s not clear at all that an attack was the culprit. Evidence suggests that organic trading and liquidation activity led to the Compound liquidations, as some Ethereum users pointed out on social media.
it does not seem like the big compound liquidation was an oracle problem.
the market price of DAI was $1.30 in a real market with real trading.
it is not even clear if it was manipulation. panic buying DAI to prevent a CDP liquidation as ETH fell is completely pluasible./
— scottlewis.canto (@scott_lew_is) November 26, 2020
Strength in Numbers?
Much of the complains levelled at Compound over the last 24 hours have to do with the fact that the DeFi protocol was overly reliant on a singular price feed, Coinbase’s.
Yet this isn’t exactly the case: Compound’s price oracle also incorporates time-weighted average prices (TWAPs), i.e. price oracles, from leading decentralized exchange for further assurances. As Uniswap creator Hayden Adams commented on Thursday:
“From what I’ve heard, the compound liquidations would have been much worse without the addition of [Uniswap] TWAPs to the Compound oracle … While the Coinbase oracle price spiked, Uniswap TWAPs did not increase much, causing the most extreme prices to be rejected.”
This is certainly validating for Uniswap’s TWAPs, but it also highlights that Compound’s price oracle performance was further strengthened by such multi-dimensionality. And for the folks who critiqued Compound for its latest major liquidations, that was the crux of the matter: that Compound would have been even better served by using many price oracles rather than less than few.
Chainlink’s Nazarov Chimes In
Chainlink is the premier decentralized oracle solution in DeFi today, and its price feeds already power an impressive range of DeFi projects. That includes lending protocol to Aave, which generally works somewhat similarly to Compound but relies instead on Chainlink’s decentralized oracles.
Aave’s worth highlighting here, then, because its Chainlink-powered Dai markets didn’t experience a raft of liquidations like Compound’s did. That’s on account of Chainlink bundling a range of price feeds rather than just relying on one.
On the news, Blockonomi reached out to Chainlink co-founder Sergey Nazarov to see what he thought the latest Compound liquidation episode represented for DeFi. In a statement shared with Blockonomi, Nazarov noted:
“We predicted this exact exploit more than a year ago, spoke publicly about this attack vector at multiple conferences, and issued a public advisory for the wider developer community. During this specific exploit, the Chainlink network performed as expected thanks to its extensive decentralization at both the node and data source levels, returning an accurate global price for these assets. Throughout this exploit, combined with high gas prices, DeFi smart contracts consuming data from the Chainlink network remained unaffected and accurate in the proper operation of their protocols.”
In the very least, then, this Compound incident should have more than a few DeFi projects doubling down on defense by exploring how to integrate with Chainlink’s oracle tech.
