The following tables summarize the aggregate hypothetical increase (decrease) in fair value in our fixed maturity investments and short term investments, private credit funds and term loans, from an immediate parallel shift in credit spreads, assuming the treasury yield curve remains constant, reflecting the use of an immediate time horizon since this presents the worst-case scenario: Credit Spread Shift in Basis Points At December 31, 2021 -100 -50 Base 50 100 (in thousands, except percentages) Fair value of fixed income and short term investments $ 18,805,516 Fair value of private credit $ 473,112 Fair value of term loans $ 74,850 Total fair value $ 19,546,182 $ 19,467,319 $ 19,353,478 $ 19,206,525 $ 19,059,573 Net increase (decrease) in fair value $ 192,704 $ 113,841 $ — $ (146,953) $ (293,905) Percentage change in fair value 1.0 % 0.6 % — % (0.8) % (1.5) % Credit Spread Shift in Basis Points At December 31, 2020 -100 -50 Base 50 100 (in thousands, except percentages) Fair value of fixed income and short term investments $ 18,500,238 Fair value of private credit $ 144,556 Fair value of term loans $ — Total fair value $ 18,900,852 $ 18,803,290 $ 18,644,794 $ 18,456,750 $ 18,269,003 Net increase (decrease) in fair value $ 256,058 $ 158,496 $ — $ (188,044) $ (375,791) Percentage change in fair value 1.4 % 0.9 % — % (1.0) % (2.0) % We also employ credit derivatives in our investment portfolio to either assume credit risk or hedge our credit exposure. At December 31, 2021, we had outstanding credit derivatives of $Nil in notional positions to hedge credit risk and $218.5 million in notional positions to assume credit risk, denominated in U.S. dollars (2020 - $Nil and $96.8 million, respectively). Refer to “Note 19. Derivative Instruments” in our “Notes to the Consolidated Financial Statements” for additional information related to credit derivatives entered into by us. The aggregate hypothetical market value impact from an immediate upward shift in credit spreads of 100 basis points would cause a decrease in the market value of our net position in these derivatives of approximately $9.1 million at December 31, 2021. Conversely, the aggregate hypothetical market value impact from an immediate downward shift in credit spreads of 100 basis points would cause an increase in the market value of our net position in these derivatives of approximately $9.1 million a t December 31, 2021. For an immediate downward shift in credit spreads, we do not allow credit spreads to go negative in calculating the impact. The foregoing reflects the use of an immediate time horizon, since this presents the worst-case scenario. 113