Shortfall: This is the difference between a position's Debt Value and the Borrowable Limit, and occurs when a position's Debt Value is higher than the Borrowable Limit. When there is a Shortfall (i.e. Position's Debt Value - Borrowable Limit ≥ 0), the position has overextended itself and must be liquidated to prevent bad debt. (However, since AUSD is overcollateralized, there is still a conservative buffer between when Shortfall reaches 0 and the point at which bad debt could occur)