"But that's weird too, because not every bank has the same funding cost. It would be odd if, say, JPMorgan (5-year CDS in the 60s) was willing to pay more to do a derivative trade than Goldman Sachs (high 80s), just because it funds more cheaply. Presumably that sometimes happens,6 but mostly people trade based on market prices, and in theory at least there should be one market price. How do you calculate that market price? Probably you can take your own credit spread into account, but presumably also there are some disconnects. So if "the market" charges 50 basis points of FVA, and your own funding costs blow out to be, say, 200 basis points, then the value of the derivative receivable to you is less than its market value."