
(In Thousands)	March 31, 2022		December 31, 2021
Servicer advance investments	$	302,837	$	350,923
HEIs	227,133		192,740
Excess MSRs	43,023		44,231
Strategic investments	40,524		35,702
Mortgage servicing rights	19,739		12,438

Other	2,325		5,935
Total Other Investments	$	635,581	$	641,969

We and a third-party co-investor, through two partnerships (“SA Buyers”) consolidated by us, purchased the outstanding servicer advances and excess MSRs related to a portfolio of legacy residential mortgage-backed securitizations serviced by the co-investor (Refer to Note 10 to the Consolidated Financial Statements included in our Annual Report on Form 10-K for the year ended December 31, 2021 for additional information regarding the transactions). At March 31, 2022, we had funded $148 million of total capital to the SA Buyers (see Note 16 for additional detail).

At March 31, 2022, our servicer advance investments had a carrying value of $303 million and were associated with a portfolio of residential mortgage loans with an unpaid principal balance of $12.70 billion. The outstanding servicer advance receivables associated with this investment were $266 million at March 31, 2022, which were financed with short-term non-recourse securitization debt (see Note 13 for additional detail on this debt). The servicer advance receivables were comprised of the following types of advances at March 31, 2022 and December 31, 2021.


(In Thousands)	March 31, 2022		December 31, 2021
Principal and interest advances	$	87,083	$	94,148
Escrow advances (taxes and insurance advances)	138,465		172,847
Corporate advances	40,401		43,958
Total Servicer Advance Receivables	$	265,949	$	310,953

We account for our servicer advance investments at fair value and during the three months ended March 31, 2022 and 2021, we recorded $5 million and $3 million of interest income, respectively, through Other interest income, and recorded a net market valuation loss of $3 million and loss of $0.2 million, respectively, through Investment fair value changes, net in our consolidated statements of income.

In 2019, we began purchasing home equity investment contracts from a third party under a flow purchase agreement. 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.

During the third quarter of 2021, we amended our original flow purchase agreement with the third party and committed to purchase $125 million of HEIs from the date of the amended agreement, and during the first quarter of 2022, we exercised an option and committed to acquire an additional $125 million of HEIs. At March 31, 2022, we had acquired $117 million of HEIs cumulatively, including $70 million of our $250 million commitment, under the third-party flow purchase agreement.

As of March 31, 2022, we owned $74 million of HEIs at Redwood and consolidated $153 million of HEIs through the HEI securitization entity. We account for these investments under the fair value option and during the three months ended March 31, 2022 and 2021, we recorded a net market valuation gain of $1 million and a net market valuation gain of $5 million, respectively, related to HEIs owned at Redwood through Investment fair value changes, net on our consolidated statements of income.

We consolidate the HEI securitization in accordance with GAAP and have elected to account for it under the CFE election. During the three months ended March 31, 2022, we recorded net market valuation gains of $3 million (including $1 million of interest expense) related to our net investment in the HEI securitization entity through Investment fair value changes, net on our consolidated statements of income.

Strategic investments represent investments we have made in companies either through our RWT Horizons venture investment platform or separately at a corporate level. At March 31, 2022, we had made a total of 21 investments in companies through RWT Horizons with a total carrying value of $25 million, and two corporate-level investments, including our strategic investment in Churchill Finance. During the three months ended March 31, 2022, we recorded $0.1 million of Other income from our strategic investments.

In association with our servicer advance investments described above, we (through our consolidated SA Buyers) invested in excess MSRs associated with the same portfolio of legacy residential mortgage-backed securitizations. Additionally, we own excess MSRs associated with specified pools of multifamily loans. We account for our excess MSRs at fair value and during the three months ended March 31, 2022 and 2021, we recognized $4 million and $3 million of interest income, respectively, through Other interest income, and recorded net market valuation losses of $1 million and $2 million, respectively, through Investment fair value changes, net on our consolidated statements of income.

We invest in mortgage servicing rights associated with residential mortgage loans and contract with licensed sub-servicers to perform all servicing functions for these loans. The majority of our investments in MSRs were made through the retention of servicing rights associated with the residential jumbo mortgage loans that we acquired and subsequently sold to third parties. During the three months ended March 31, 2022, we retained $5 million of MSRs from sales of residential loans to third parties. We hold our MSR investments at our taxable REIT subsidiaries.

At March 31, 2022 and December 31, 2021, our MSRs had a fair value of $20 million and $12 million, respectively, and were associated with loans with an aggregate principal balance of $2.36 billion and $2.12 billion, respectively. During the three months ended March 31, 2022 and 2021, including net market valuation gains and losses on our MSRs, we recorded net income of $4.3 million and $1 million, respectively, through Other income on our consolidated statements of income related to our MSRs.