Notes to consolidated financial statements The following table presents the components of mortgage fees and related income (including the impact of MSR risk management activities) for the years ended December 31, 2020, 2019 and 2018. (a) Represents both the impact of changes in estimated future prepayments due to changes in market interest rates, and the difference between actual and expected prepayments. (b) Represents the aggregate impact of changes in model inputs and assumptions such as projected cash flows (e.g., cost to service), discount rates and changes in prepayments other than those attributable to changes in market interest rates (e.g., changes in prepayments due to changes in home prices). The table below outlines the key economic assumptions used to determine the fair value of the Firm’s MSRs at December 31, 2020 and 2019, and outlines the sensitivities of those fair values to immediate adverse changes in those assumptions, as defined below. (a) Includes the impact of operational risk and regulatory capital. Changes in fair value based on variations in assumptions generally cannot be easily extrapolated, because the relationship of the change in the assumptions to the change in fair value are often highly interrelated and may not be linear. In this table, the effect that a change in a particular assumption may have on the fair value is calculated without changing any other assumption. In reality, changes in one factor may result in changes in another, which would either magnify or counteract the impact of the initial change. JPMorgan Chase & Co./2020 Form 10-K 264 December 31, (in millions, except rates) 2020 2019 Weighted-average prepayment speed assumption (constant prepayment rate) 14.90 % 11.67 % Impact on fair value of 10% adverse change $ (206) $ (200) Impact on fair value of 20% adverse change (392) (384) Weighted-average option adjusted spread 7.19 % 7.93 % Impact on fair value of 100 basis points adverse change $ (134) $ (169) Impact on fair value of 200 basis points adverse change (258) (326) (a) Year ended December 31, (in millions) 2020 2019 2018 CCB mortgage fees and related income Net production revenue $ 2,629 $ 1,618  $ 268  Net mortgage servicing revenue: Operating revenue: Loan servicing revenue 1,367 1,533  1,835  Changes in MSR asset fair value due to collection/realization of expected cash flows (899) (951) (740) Total operating revenue 468 582  1,095  Risk management: Changes in MSR asset fair value due to market interest rates and other (1,568) (893) 300  Other changes in MSR asset fair value due to other inputs and assumptions in model 28 (287) (70) Change in derivative fair value and other 1,522 1,015  (341) Total risk management (18) (165) (111) Total net mortgage servicing revenue 450 417  984  Total CCB mortgage fees and related income 3,079 2,035  1,252  All other 12 1  2  Mortgage fees and related income $ 3,091 $ 2,036  $ 1,254  (a) (b)