Expo

 How Decentralized is it?

• Was classified Degree 2 DeFi on the HackerNoon rankings of 25-4-2019. "These DeFi products are non-custodial and have one additional decentralized component which could include price feeds, initiation of margin calls, margin liquidity, interest rate determination, or platform development, while the rest are still centralized."
• A BIG side note, is that the blog was written by Kyle J Kistner who is Chief Vision Officer at bZx. He gave his own project the highest ranking. What a surprise.

• From the comprehensive blog post:

"Custody: The Expo contracts are open-source and non-custodial from the point of loan origination.

Initiating Margin Calls: Expo centrally monitors margin positions, and calls into their contracts when a position has gone under margin maintenance. Only dYdX’s whitelisted address can call into the contract to initiate the margin call, making this a central point of failure.

Margin Call Liquidity: When a margin call is initiated, the Expo contracts initiate a Dutch Auction. Currently, Expo centrally provides liquidity during the Dutch Auction using RadarRelay and ETH2DAI. In theory, other parties could participate, however none do, perhaps owing to the lack of an intuitive interface.

Price Feeds: Due to the use of a Dutch Auction, no price feed is required, making this component decentralized.

Interest Rates: Expo interest rates are centrally determined and static.

Development: The Expo contracts are centrally developed and open source. The contracts are largely not mutable, but there are a number of opt-in upgrades available such as ETH wrapper proxy contracts and additional decentralized exchange wrappers."