OIP-165: The Framework - Yield Repurchase Facility

Snapshot note: this was originally posted on the forum as OIP-164 which is already taken by another proposal. To avoid collision, the number has been incremented to 165.

Summary:

This proposal expands on OIP-163 (The Framework), implementing the same proposal with improved infrastructure via the Yield Repurchase Facility (YRF).

Proposal:

Implement the YRF, which uses Axis Finance (formerly known as Bond) protocol markets to convert DAI into OHM. The YRF calculates inventory to convert each week based on the increase in the redemption value of sDAI in the clearinghouse and treasury over the preceding week (sDAI yield accrued), in addition to yield on Cooler loans calculated as principal receivables times 0.5% divided by 52 weeks. Note that the usage of Cooler interest is an addition from the previous proposal.

The YRF has an overseer, to be assigned to the current repurchase multisig, with the following permissions: to adjust the next weeks yield by -100% < X < +10% in case the expenditure is miscalculated; and to shutdown the facility and transfer any DAI or other tokens back to the treasury.

The YRF burns repurchased OHM at the end of each day and redeems them for 11.33 DAI each, to be used as inventory for the following day. This reduced backing number ensures the system remains properly collateralized and will not overspend even in case of fluctuations in the market value of volatile treasury assets like OHM-WETH POL.

Implementation:

The YRF can be activated via the provisioning of treasury withdrawer approval, in addition to the deployment of an upgraded Heart contract to update it at the start of each epoch.

Motivation:

Increase the automation and resilience of a component of the Olympus protocol.