Per-contract underwriting
Problem
In a shared pool where every deposit owns a share of everything, timing is unfair. An underwriter who deposits the day before a large premium arrives shares it with those who carried the risk for weeks. One who deposits the day before a large payout shares a loss on contracts they never chose to back. Share-based pools also need a share price, which depends on how unexpired contracts are valued.
Approach
Each contract records its funders: the underwriters whose free money was reserved for it, and how much each reserved.
- At sale, the reserve is split across current backers in proportion to their free money, and the net premium is credited to them in the same proportion, at once.
- At settlement, the payout is charged only to those funders, in proportion to their reserve.
There are no pool shares. Each underwriter has a plain balance: free, reserved, earned, paid.
Why
- Fair by construction. Premium and risk go to the same people, in the same proportions, for the same contract.
- No valuation of open contracts. Nobody needs a mark-to-model price to deposit or withdraw.
- Instant withdrawals of free money. Free money backs nothing, so it can leave at any time.
- Choice. Underwriters can stop backing new sales or limit tenor without leaving.
Trade-offs
- Gas and storage per contract grow with the number of funders. The pool caps underwriters at 50.
- Concentration. If one underwriter holds most of the free money, they back most new contracts.
- Premium is credited before risk is known. An underwriter can withdraw a premium while still carrying the reserve that earned it. The reserve stays locked, so the pool remains solvent.