In this example, there is a total of $100m collateral for all tAssets in the market. As overall tAssets price increases, the Collateral Ratio decreases. From the change in Collateral Ratio, there is now $250,000 of KUSD which is now overcollateralized and is open for buyback to happen. When buyback happens, surplus KUSD is withdrawn to the person who does the buyback, and provided TWX of the same value will be burned from the system.