Tier 2 (Collateral Auction): If a position is below margin maintenance and Tier 1 (described above) has failed to close the position, anyone who calls liquidate() will be entitled to purchase the collateral from the insolvent account at a discount. The collateral is valued using Chainlink price feeds. Each collateral has its own discount factor depending on the risk parameters of the asset. Both the volatility and depth of liquidity will be considered when determining the discount factor for any given collateral. Liquidators face two main risks when liquidating collateral: that the price changes while they hold it (volatility risk), and that the slippage turns the liquidation unprofitable (liquidity risk). Generally, the discount applied during the collateral auction will reflect the overall depth of liquidity available to that asset across all exchanges. Since liquidation penalties from collateral auctions can be significant, it is in the best interest of borrowers and traders to either close the position in a timely manner or enable Fulcrum Saver.