Table of Contents The earnings simulation model excludes the earnings dynamics related to how fee income and noninterest expense may be affected by changes in interest rates. Actual results may differ materially from those projected. The use of this methodology to quantify the market risk of the balance sheet should not be construed as an endorsement of its accuracy or the accuracy of the related assumptions. At December 31, 2020 and 2019, the impact of these hypothetical fluctuations in interest rates on our derivative holdings was not significant, and, as such, separate disclosure is not presented. We manage the interest rate risk related to mortgage loan commitments by entering into contracts for future delivery of loans with outside parties. See Part II, Item 8, Financial Statements and Supplementary Data — Note 18 of the Notes to Consolidated Financial Statements. Commitments and Contractual Obligations  — In the ordinary course of operations, we enter into certain contractual obligations. Such obligations include customer deposits, the funding of operations through debt issuances as well as operating leases for the rent of premises and equipment. Additionally, we routinely enter into contracts for services that may require payment to be provided in the future and may contain penalty clauses for early termination of the contract. Further discussion of commitments and contractual obligations is included in Part II, Item 8, Financial Statements and Supplementary Data — Notes 10, 11, 12 and 18 of the Notes to Consolidated Financial Statements. We also enter into derivative contracts under which we are required to either receive cash from, or pay cash to, counterparties depending on changes in interest rates. Derivative contracts are carried at fair value on the consolidated balance sheet with the fair value representing the net present value of expected future cash receipts or payments based on market interest rates as of the balance sheet date. The fair value of the contracts changes daily as market interest rates change. Further discussion of derivative contracts is included in Part II, Item 8, Financial Statements and Supplementary Data — Note 19 of the Notes to Consolidated Financial Statements. Assets under management and assets under custody are held in fiduciary or custodial capacity for our clients. In accordance with U.S. generally accepted accounting principles, these assets are not included on our balance sheet. We are also party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of our clients. These financial instruments include commitments to extend credit and standby letters of credit. Further discussion of these commitments is included in Part II, Item 8, Financial Statements and Supplementary Data — Note 18 of the Notes to Consolidated Financial Statements. OFF-BALANCE SHEET ARRANGEMENTS 42