Four-Tier Defense System

Aspan does not rely on a single line of defense but builds a multi-layered defense network:

L1: Economic Incentives

• Status: CR < 150% (Warning Zone)

• Mechanism: Dynamic fee system activates automatically

• Actions: Waive xBNB minting fees, or even offer minting discounts

• Effect: Attract arbitrageurs to actively inject capital and pull CR back to the safe zone

L2: System Rebalancing

• Status: CR < 130% (Danger Zone)

• Mechanism: Forced deleveraging

• Actions: The protocol automatically burns apUSD in the Stability Pool and converts it to xBNB

• Effect: Rapidly reduce system debt and prevent a death spiral. This is the core defense mechanism.

L3: Protocol Recapitalization

• Status: CR < 110% (Extreme Emergency)

• Mechanism: Deploy treasury reserves

• Actions: The Aspan protocol will use accumulated Treasury Reserves or issue debt tokens to buy back and burn apUSD on the market

• Effect: Act as the Lender of Last Resort to rigidly maintain the peg

L4: Emergency Circuit Breaker

• Status: Severe LST depeg or oracle failure

• Mechanism: Global pause

• Actions: The Guardian triggers pause() to freeze all Mint/Redeem functions

• Effect: Prevent the treasury from being drained by erroneous prices, waiting for the market to recover rationality or for community voting to resolve the issue