Sharing Debt Pool

Once a user mints some synthetic assets, the assets can be put into the sharing debt pool (SDP), and the user will be assigned a fixed debt ratio which is the ratio of the value of the user's synthetic assets to the value of all synthetic assets in the entire system . "Fixed" means this ratio will not change due to changes in asset prices, and will be used to calculate the user's profit and loss. This ratio will only change when a new user mints new assets or an existing user destroys existing assets.

Bellows are three examples to illustrate how we calculate every user's debt ratio.

Example 1: Assuming that there are only two users in the system, A and B, A and B each generate rUSD worth $100 after collateralizing a certain amount of CRF, that is, the system generates a total of $200 rUSD. At this time, the debt ratio of user A is 100/200=50%, and the debt ratio of user B is also 100/200=50%.

Example 2: Immediately following Example 1, suppose another new user C joins and newly generated rBTC worth $200. At this time, the total assets of the system are rUSD $200 and rBTC$200, which is a total of $400. Therefore, the debt ratio of users A and B is adjusted to 100/400=25%, and the debt ratio of new user C is 200/400=50%.

Example 1 illustrates the generation of debt ratio in the initial state of the system, and Example 2 illustrates how new users will affect the re-division of debt ratio. What follows is an example of a more general situation.

Example 3: Assume that the entire system has generated a synthetic asset of $100K, and now a new user X has joined and generated a synthetic asset of $100. Then the debt ratio of user X is 100/(100+100000)=0.0999%. Suppose that there was an old user A whose debt ratio was 0.2%. After X is added, the debt ratio of user A becomes 0.2%×100000/(100+100000)=0.1998%. By analogy, we can calculate the change in the debt ratio of all users.