Before revision:  Second, we show thatcomputing an approximate solution to the clearing problem with sufficiently small constant error is PPAD-complete  .
After revision:  Second, we show thatcomputing an approximate solution to the clearing problem with sufficiently small constant error is PPAD-complete for constant \varepsilon. We then try to isolate the "origin" of the complexity. It turns out that already determining which banks default is hard. Further, we show that the complexity is not driven by the dependence of counterparties on each other, but rather hinges on the presence of so-called naked CDSs .