Arrow's Automated Hedging Engine (AHE) tracks the AMM's option obligations.

Delta Hedging

The Arrow system runs an automated hedging engine to offset changes in the risk profile of the trading pool due to underlying price movements. This works as follows. Along with prices, the AMM calculates a
(a "delta") or hedge position for each new option added or removed from the system. We use both BSM deltas and skew-adjusted deltas computed using the SVI model implied volatility. For call options, the deltas are
Δbsm=N(d1(σsvi))Δskew=Δbsm+vegasvisvi\Delta_{bsm} = N(d_{1}(\sigma_{svi})) \\ \Delta_{skew} = \Delta_{bsm} + \text{vega}_{svi} \partial_{svi}
The skew-adjusted delta corrects the BSM delta with a term that multiplies the contract's vega (using the SVI IV) by the slope of the SVI curve at the contract's moneyness,
The smart contract that houses the trading pool balances then takes that
and picks up the corresponding balance in the underlying. If the net
is positive, the position is obtained by programmatically swapping stable coin for the underlying (or vice-versa, depending on the sign of the option
) on a DEX such as Pangolin or Trader Joe.
If the net
is negative, the position is obtained by programmatically interacting with an on-chain lending protocol such as BenQi or Banker Joe. In the latter case, if the option
is negative, the short position in the underlying is increased, and if the option
is positive, the short position is decreased.