In the recently updated Hertz whitepaper, the possible layers of MPA backing collateral were defined as the following, accounting for their level of publicly proven backing collateral.
| MPA Layer | Backing Collateral | Examples | MPA Layer Justification |
|---|---|---|---|
| 0 | UIA | N/A – e.g. USD MPA backed by UIA | UIA backing lacks proof of collateral on the blockchain |
| 0 | L0 MPA (UIA backed MPA) | N/A – e.g. Index MPA backed by L0 MPA | L0 backing lacks proof of collateral on the blockchain |
| 1 | ACCT UIA | N/A – ACCT is a future planned feature | ACCT has proven backing collateral, thus it’s trustless unlike EBAs. |
| 1 | BTS (Core token) | bitUSD, bitCNY, Hertz, Hero | BTS backing collateral proven on blockchain. |
| 2 | L1 MPA | XCD (backed by bitUSD) | MPA backing which has proven BTS backing |
These layers are not defined in the Bitshares reference docs on MPA, rather an unofficial community created definition. If you disagree with the layer definitions then do reply with suggestions for improvement.
The following sub-sections will describe each layer.
MPA which are backed either by an User Issued Asset (UIA) or an UIA backed MPA do not have publicly proven backing collateral; they require trust to be placed in the hands of gateway services and for this reason they are categorized as layer 0 MPA.
Once Atomic Cross Chain Transfers (ACCT) are implemented on the BTS DEX in manner that's fully trustless then we can assume a level of confidence in the existence of the relevant backing collateral on the blockchain.
Bitshares (BTS) when used as backing collateral for an MPA provides full proof of collateral on the blockchain once borrowed into existence.
For an MPA to be categorized as layer 1, there needs to be proof of backing collateral on the blockchain.
MPA which are backed by any layer 1 MPA (ACCT|BTS backed) have proven backing collateral double locked on the BTS DEX. Layer 2 MPA experience greater separation from BTS' price volatility as they are
The reason that MPA backed by L0 MPA aren't L2 is that despite the UIA backing being double locked, proof of backing collateral doesn't exist on the blockchain for the UIA.
We've mentioned L2 MPA and MPA backed by UIA backed MPA, however we haven't provided any further layer definitions nor triple+ locked MPA collateral. The reason for this is that you "May not create a bitasset backed by a bitasset backed by a bitasset." - the triple locked MPA is not permitted.
It's always been possible to create an MPA which is backed by an UIA (L0), but it's only been possible via the CLI not through the UI, which has prevented users from experimenting with such MPA configurations. Soon UIA will be a permitted MPA backing type within the UI!
After the above change is in place, I believe we'll begin to see more L0 MPA being created on the BTS DEX which is great for the reserve pool but perhaps not great if used maliciously.
Post below & I'll respond to any questions you have 👍
CM
