Lyra Documentation
Search…
⌃K

## Partial Collateralization

Options that are shorted (sold) to the AMM by users need to be collateralized. By selling an option, a trader is now responsible for the payout to the AMM at settlement so they need to post collateral to cover the short option.
Newport allows users to partially collateralize their shorts, greatly improving capital efficiency. This would mean, selling 1 ETH call would require, say, 0.4 ETH - a substantial improvement over V1. Further, short calls will now be able to be collateralized in either the base (ETH, BTC, etc) or quote asset (USDC or sUSD). Short puts will only be able to be collateralized with the quote asset.
When a user collateralizes an option with a quote asset (USDC, sUSD), the premium is received upfront. This means that a trader shorting an option will have their premium added to their collateral and have a debt to the system which fluctuates based on the value of the short option. The flow is as follows: the trader wants to sell an option worth $100, they collateralize it with$1000, send $900 to the contract and keep the$100 premium. The trader now owes a debt of the value of the options (currently $100). If the option settles OTM, the trader will receive$1000, if the option expires ITM, say $200, the trader will receive$800 at expiry.
When a user collateralizes an option with a base (ETH, BTC, etc) asset, instead of the premium being added to their collateral, it is simply sent to their wallet. At expiry, if the option is ITM, the dollar value is removed from their collateral, e.g. the option settles at $200, ETH is worth$2000; they have posted 0.5 ETH as collateral. They will receive back ~0.4 ETH (less swapping fees).
Users will always have the option to fully collateralize their shorts (and so have no chance of being liquidated - see next section). In order to use partial collateralization, a user must deposit a minimum amount of collateral.
The minimum amount of collateral (in the base asset) for a short is computed by finding the premium of the same option with a time-dependent shock volatility and a static percentage shock to the spot price. Specifically, the minimum amount of collateral required will be given by:
$MinCollateral = \max(\texttt{MinStaticCollateral},BS(\texttt{ShockVol},K,S\times \texttt{SpotShock},r,T)$
Where MinStaticCollateral is the absolute minimum amount of collateral required for any (partially collateralized) short. Here, ShockVol is a large, time-dependent static volatility while SpotShock is a static percentage shock to the spot price.
Users must maintain at least the minimum amount of collateral or they will be liquidated by a liquidator. For more details on this, see the next section on Liquidations.

## Liquidations

When a user's collateral falls below the minimum collateral (described in the previous section) they are eligible to be liquidated. This occurs via keepers, users who call the liquidation function on an underwater position.
When a user is liquidated, the user is forced to buy back their option in such a way that will (in expectancy) favour the AMM/LPs.
The user's remaining liquidity will then be penalized by a flat percentage, for more detail see . This slashed penalty will then be split between the liquidator, the AMM, and the security module.

Partial cash collateralization for options means that the liquidity pool is open to insolvency when the netOptionDebt exceeds the netAssetValue of the LP. In order to address this issue, values for long holders will be reduced by a certain percentage that makes the LP solvent again. This is calculated using the AdjustmentNetValueScalingFactor, parameter that caps the total value of the pool that is used to scale down longs. When an option is closed or settled, the option value will be scaled down by the percentage (scaledNetValue / netOptionDebt) which makes the pool solvent again before funds are transferred to the user. A circuit breaker (contractAdjustmentCBTimeout) must be added to make sure deposits and withdrawals are frozen for the duration of any contract adjustment event.