Early payouts

A date can only be closed when every loan at it has ended. One unpaid loan can take up to about 5 weeks to end (see the time limit). Early payouts mean that loan delays only its own share: everything already collected for the date can be withdrawn from the Thursday on.

How it worksCopy Anchor Link

Once the Thursday has passed, a unit holder calls withdrawCollected(maturity, units):

1. The units are burned from the caller and added to the caller's Claim for that date. A Claim belongs to that address and cannot be transferred, so units moved into it can no longer be sold or sent.
2. The Claim is owed its share of everything collected so far, worked out on its whole history:

MUSD owed = the smaller of: units, or units x collected MUSD / every unit ever issued at the date
BTC owed  = units x collected BTC / every unit ever issued at the date

3. The Claim is paid what it is owed minus what it was already paid. Calling again later, with zero new units, pays only what arrived since.

On Lend this is "Withdraw what's collected", then "Withdraw the new part". See Credit units and payouts.

Why it is fairCopy Anchor Link

• No new units can be added to a date once its Thursday has passed, so the total of units is fixed and each unit's share only grows.
• The share is recomputed on the Claim's whole history every time, so rounding never builds up across withdrawals.
• A unit receives the same total whichever path it takes, early withdrawals, a late redemption or a mix, within a few wei of rounding. Nobody gains by withdrawing first.
• The MUSD part never exceeds 1 MUSD per unit, and the date never pays out more than it collected.

For example, take a date with 1,000 units in total and 600 MUSD collected so far. A holder of 100 units can withdraw 60 MUSD now. When the last 400 MUSD arrives, the same holder withdraws 40 more.

Redemption after the date closesCopy Anchor Link

When every loan at the date has ended, anyone can close it with finalize, which freezes the totals. Units still in a wallet are then redeemed with redeem: the units are burned first, and the holder is paid units x MUSD at close / units at close (capped at 1 MUSD per unit) plus the same share of any BTC, both rounded down. A holder with a Claim takes the rest of it with one more withdrawCollected.

The protocol's own units follow the same rules, so the fee shares losses with lenders at the same rate.