During the year ended December 31, 2021, we leased additional office space and extended the lease term at two of our office locations and determined that each of these lease amendments qualified as operating leases. At December 31, 2021, our operating lease liabilities were $21 million, which were a component of Accrued expenses and other liabilities, and our operating lease right-of-use assets were $19 million, which were a component of Other assets.

We determined that none of our leases contained an implicit interest rate and used a discount rate equal to our incremental borrowing rate on a collateralized basis to determine the present value of our total lease payments. As such, we determined the applicable discount rate for each of our leases using a swap rate plus an applicable spread for borrowing arrangements secured by our real estate loans and securities for a length of time equal to the remaining lease term on the date of adoption. At December 31, 2021, the weighted-average remaining lease term and weighted-average discount rate for our leases was 6 years and 5.1%, respectively.

As of December 31, 2021, we had commitments to fund up to $625 million of additional advances on existing bridge loans. These commitments are generally subject to loan agreements with covenants regarding the financial performance of the borrower and other terms regarding advances that must be met before we fund the commitment. At December 31, 2021 and 2020, we carried a $1 million and $2 million contingent liability related to these commitments to fund construction advances, respectively. During the years ended December 31, 2021 and 2020, we recorded a net market valuation gain of $1 million and a net market valuation loss of $2 million, respectively, related to this liability through Mortgage banking activities, net on our consolidated statements of income (loss).

In 2018, we invested in two partnerships created to acquire and manage certain mortgage servicing related assets (see Note 10 for additional detail). In connection with this investment, we are required to fund future net servicer advances related to the underlying mortgage loans. The actual amount of net servicer advances we may fund in the future is subject to significant uncertainty and will be based on the credit and prepayment performance of the underlying loans.

In the third quarter of 2021, we amended an existing flow purchase agreement with Point Digital to acquire HEIs that Point Digital originates with homeowners. Each HEI provides the owner of such HEI the right to purchase a percentage ownership interest in an associated residential property, and the homeowner's obligations under the HEI are secured by a lien (primarily second liens) on the property created by a deed of trust or a mortgage. Our investments in HEIs allow us to share in both home price appreciation and depreciation of the associated property. At December 31, 2021, we had an outstanding remaining commitment to fund up to $94 million under this agreement.

During 2015 and 2016, we sold conforming loans to the Agencies with an original unpaid principal balance of $3.19 billion, subject to our risk-sharing arrangements with the Agencies. At December 31, 2021, the maximum potential amount of future payments we could be required to make under these arrangements was $44 million and this amount was fully collateralized by assets we transferred to pledged accounts and is presented as pledged collateral in Other assets on our consolidated balance sheets. We have no recourse to any third parties that would allow us to recover any amounts related to our obligations under the arrangements. At December 31, 2021, we had not incurred any losses under these arrangements. For the years ended December 31, 2021, 2020, and 2019, other income related to these arrangements was $3 million, $4 million and $4 million, respectively, and was included in Other income on our consolidated statements of income (loss). For the years ended December 31, 2021, 2020, and 2019, we recorded net market valuation losses related to these arrangements of $0.1 million, $1 million, and $0.2 million, respectively, through Investment fair value changes, net, on our consolidated statements of income (loss).

All of the loans in the reference pools subject to these risk-sharing arrangements were originated in 2014 and 2015, and at December 31, 2021, the loans had an unpaid principal balance of $552 million and a weighted average FICO score of 756 (at origination) and LTV ratio of 74% (at origination). At December 31, 2021, $18 million of the loans were 90 days or more delinquent, of which one of these loans with an unpaid principal balance of $0.2 million was in foreclosure. At December 31, 2021, the carrying value of our guarantee obligation was $7 million and included $5 million designated as a non-amortizing credit reserve, which we believe is sufficient to cover current expected losses under these obligations.

Our consolidated balance sheets include assets of special purpose entities ("SPEs") associated with these risk-sharing arrangements (i.e., the "pledged collateral" referred to above) that can only be used to settle obligations of these SPEs for which the creditors of these SPEs (the Agencies) do not have recourse to us. At December 31, 2021 and 2020, assets of such SPEs totaled $34 million and $46 million, respectively, and liabilities of such SPEs totaled $7 million and $10 million, respectively.

We maintain a repurchase reserve for potential obligations arising from representation and warranty violations related to residential loans we have sold to securitization trusts or third parties and for conforming residential loans associated with MSRs that we have purchased from third parties. We do not originate residential loans and we believe the initial risk of loss due to loan repurchases (i.e., due to a breach of representations and warranties) would generally be a contingency to the companies from whom we acquired the loans. However, in some cases, for example, where loans were acquired from companies that have since become insolvent, repurchase claims may result in our being liable for a repurchase obligation. Additionally, for certain loans we sold during the second quarter of 2020 that were previously held for investment, we have a direct obligation to repurchase these loans in the event of any early payment defaults (or EPDs) by the underlying mortgage borrowers within certain specified periods following the sales.

At December 31, 2021 and 2020, our repurchase reserve associated with our residential loans and MSRs was $9 million and $9 million, respectively, and was recorded in Accrued expenses and other liabilities on our consolidated balance sheets. We received 4 and 10 repurchase requests during the years ended December 31, 2021 and 2020, respectively. During the years ended December 31, 2021, 2020, and 2019, we repurchased two loans, one loan, and zero loans, respectively. During the years ended December 31, 2021, 2020, and 2019, we recorded repurchase provisions of $1 million and $4 million and reversals of repurchase provisions of $0.1 million, respectively, that were recorded in Mortgage banking activities, net and Other income on our consolidated statements of income (loss) and had charge-offs of $0.2 million, $0.1 million, and zero, respectively.

There is no significant update regarding the FHLB-Seattle or Schwab litigation matters referenced in Note 16 within the financial statements included in Redwood’s Annual Report on Form 10-K for the year ended December 31, 2021 under the heading "Loss Contingencies - Litigation." At December 31, 2021, the aggregate amount of loss contingency reserves established in respect of the FHLB-Seattle and Schwab litigation matters referenced in our Annual Report on Form 10-K for the year ended December 31, 2020 was $2 million.

From time to time and in the ordinary course of business, we may submit or receive demand letters to or from counterparties relating to breaches of representations and warranties, be named in lawsuits brought by mortgage borrowers relating to foreclosure proceedings initiated by the servicers of the related mortgage loans or seeking to establish that their mortgage notes and/or mortgages are unenforceable as a matter of law due to defects in the transfer and assignment of those notes and mortgages, or be named in lawsuits brought by mortgage borrowers seeking remedies against the originator of the mortgage for fraud or defects in the originator's origination process, including defects in the disclosure of mortgage terms at the time of origination (in these cases we may be named in connection with the origination of the loan, in the case of business purpose loans we originate, or on a theory of assignee liability in the case of residential loans we acquire). Additionally, following our acquisitions of the 5 Arches and CoreVest business purpose loan origination platforms, there are litigation matters that relate to these two platforms that represent a level of litigation activity that we believe is generally consistent with the ordinary course of business of a loan originator, which has not been associated with Redwood historically.

In addition to those matters, as previously disclosed, in connection with the impact of the effects of the pandemic on the non-Agency mortgage finance market and on our business and operations, a number of the counterparties that have regularly sold residential mortgage loans to us believe that we breached perceived obligations to them, and requested or demanded that we purchase loans from them and/or compensate them for perceived damages resulting from our decisions in early 2020 not to purchase certain loans from them (“Residential Loan Seller Demands”). With respect to specific lawsuits or claims arising out of or relating to Residential Seller Demands, there is no significant update regarding the matter(s) described in Note 16 within the financial statements included in Redwood's Annual Report on Form 10-K for the year ended December 31. 2020 under the heading "Loss Contingencies - Litigation, Claims and Demands".

During the year ended December 31, 2020, we recorded $10 million of expenses in association with Residential Loan Seller Demands. At December 31, 2021, the aggregate amount of our accrual for estimated costs associated with Residential Loan Seller Demands was $0.5 million, a portion of which is contingent on the successful completion of future residential loan purchase and sale transactions with certain counterparties. We believe we have either resolved or adequately accrued for any unresolved Residential Loan Seller Demands and that there are no other Residential Loan Seller Demands that are reasonably possible to result in a material loss. Our actual losses, and any accruals or reserves we may establish in the future relating to these matters, may be materially higher than the accruals and reserves we have noted above, including in the event that any of these matters proceed to trial and result in a judgment against us. We cannot be certain that any of these matters that are not already formally resolved will be resolved through a resolution or settlement and we cannot be certain that the resolution of these matters, whether through litigation, settlement, or otherwise, will not have a material adverse effect on our financial condition or results of operations in any future period.

In accordance with GAAP, we review the need for any loss contingency reserves and establish reserves when, in the opinion of management, it is probable that a matter would result in a liability and the amount of loss, if any, can be reasonably estimated. Additionally, we record receivables for insurance recoveries relating to litigation-related losses and expenses if and when such amounts are covered by insurance and recovery of such losses or expenses are due. We review our litigation matters each quarter to

In the ordinary course of any litigation matter, including certain of the above-referenced matters, we have engaged and may continue to engage in formal or informal settlement communications with the plaintiffs or co-defendants. Settlement communications we have engaged in relating to certain of the above-referenced litigation matters are one of the factors that have resulted in our determination to establish the loss contingency reserves described above. We cannot be certain that any of these matters will be resolved through a settlement prior to litigation and we cannot be certain that the resolution of these matters, whether through trial, settlement, or otherwise, will not have a material adverse effect on our financial condition or results of operations in any future period.

Future developments (including resolution of substantive pre-trial motions relating to these matters, receipt of additional information and documents relating to these matters (such as through pre-trial discovery), new or additional settlement communications with plaintiffs relating to these matters, or resolutions of similar claims against other defendants in these matters) could result in our concluding in the future to establish additional loss contingency reserves or to disclose an estimate of reasonably possible losses in excess of our established reserves with respect to these matters. Our actual losses with respect to the above referenced litigation matters may be materially higher than the aggregate amount of loss contingency reserves we have established in respect of these litigation matters, including in the event that any of these matters proceeds to trial and the plaintiff prevails. Other factors that could result in our concluding to establish additional loss contingency reserves or estimate additional reasonably possible losses, or could result in our actual losses with respect to the above-referenced litigation matters being materially higher than the aggregate amount of loss contingency reserves we have established in respect of these litigation matters include that: there are significant factual and legal issues to be resolved; information obtained or rulings made during the lawsuits could affect the methodology for calculation of the available remedies; and we may have additional obligations pursuant to indemnity agreements, representations and warranties, and other contractual provisions with other parties relating to these litigation matters that could increase our potential losses.