Privacy is the product
Deposit CBTC. Overwrite writes weekly physically-settled covered calls on Canton and pays the premium straight to holders on-chain. Your position is a contract between you and the vault, and the rest of the market cannot read it.
A demo build on the Canton devnet. The market maker and the price feed are simulated, and every premium figure is a demo parameter. No wallet needed: the demo parties are pre-funded and backend-custodied.
Why Canton
Switch between two depositors in the app and each sees only their own position, from the same vault in the same epoch. Only the operator and one depositor are parties to a position, so only they can read it. That is the Daml signatory and observer model doing the work, not a filter in the interface. The server renders what that party can read, and nothing else.
At expiry the locked CBTC and the strike cash move in one transaction, or neither moves. There is no escrow contract to trust and no public mempool to be front-run in.
Every epoch the vault transfers premium to each holder and writes each of them a receipt. Nothing sits in a claimable balance waiting to be harvested.
How it works
The vault runs in epochs. A production epoch is a week; this demo compresses it to minutes so you can watch a whole one. Every step below is a state change on the ledger.
Holders deposit CBTC while the window is open. Each deposit becomes a VaultPosition signed by the operator and that one depositor, and by nobody else.
The deposited CBTC moves into a CIP-56 allocation through the token registry and stays locked there for the life of the option.
The vault issues a CallOption and the market maker pays the premium. Each holder receives their own transfer and their own PremiumReceipt.
The settlement price decides which. Only one of these runs, and the ledger records which one it was.
If the settlement price is at or below the strike, the collateral is released back to holders and they keep the premium.
If the settlement price is above the strike, the locked CBTC and the strike cash change hands in one atomic delivery-versus-payment transaction.
An EpochReport records the aggregate result and no per-holder payout list. Positions with no queued withdrawal roll into the next epoch.
Privacy
On an EVM option vault, anyone can read the depositors, the vault size, the strikes, and the roll schedule, and market makers price against that flow. On Canton, a position is a contract between two parties and only those parties can see it.
EVM option vaults
Overwrite on Canton
Limits
Collateral is locked on-chain for the life of the option, so the buyer carries no unsecured exposure to the vault. That is a narrower claim than counterparty-risk-free, which we do not make.
This is a hackathon build. The market maker that pays the premium and the price feed that settles the option are both simulated, and labeled that way everywhere they appear.
Every premium number in the app is a demo parameter, not a quote and not market pricing. Overwrite publishes no yield and no APY.
The vault only transfers and allocates CBTC. Mint and burn are institution-gated, and this app never calls them.
Switch between two depositors and watch one ledger show each of them only their own book. Then try the observer, who is a stakeholder of nothing and sees exactly that.
Open the app