Within our correspondent lending channel, we generally purchase the same types of loans that we originate in our consumer originations channel, although the mix varies among these channels. Correspondent lenders with which we do business agree to comply with our client guide, which sets forth the terms and conditions for selling loans to us and generally governs the business relationship. We monitor and attempt to mitigate counterparty risk related to loans that we acquire through our correspondent lending channel by conducting quality control reviews of correspondent lenders, reviewing compliance by correspondent lenders with applicable underwriting standards and our client guide, and evaluating the credit worthiness of correspondent lenders on a periodic basis. In 2018, our correspondent lending channel purchased loans from 452 lenders in the marketplace, of which 38 were associated with approximately half of our purchases.
Within our wholesale lending channel, we originate loans through mortgage brokers. Loans sourced by mortgage brokers are underwritten and funded by us and generally close in our name. Through the wholesale channel, we generally originate the same types of loans that we originate in our consumer originations channel, although the mix varies among these channels. We underwrite and process all loan applications submitted by the mortgage brokers in a manner consistent with that described above for the consumer originations channel. Mortgage brokers with whom we do business agree to comply with our client guide, which sets forth the terms and conditions for brokering loans to us and generally governs the business relationship. We monitor and attempt to mitigate counterparty risk related to loans that we originate through our wholesale lending channel by conducting quality control reviews of mortgage brokers, reviewing compliance by brokers with applicable underwriting standards and our client guide, and evaluating the credit worthiness of brokers on a periodic basis.
Our capital markets group is responsible for pricing loans and managing the interest rate risk through the time a loan is sold to third parties and managing the risk (which we call the “pull-through risk”) that loans we have locked will not be closed and funded in an attempt to maximize loan sale profitability through our various originations channels. The capital markets group uses models and hedging analysis in an attempt to maximize profitability while minimizing the risks inherent in the originations business.
In 2018, the mix of mortgage loans sold by our Originations segment, based on unpaid principal balance, consisted of (i) 57% Ginnie Mae loans, (ii) 30% Fannie Mae conventional conforming loans and (iii) 13% Freddie Mac conventional conforming loans.
Our Originations segment revenue, which is primarily net gains on sales of loans, is impacted by interest rates and the volume of loans locked. The margins earned by our Originations segment are impacted by our cost to originate the loans including underwriting, fulfillment and lead costs.
Reverse Mortgage Segment
Our Reverse Mortgage segment primarily focuses on the servicing of reverse loans. Effective January 2017, we exited the reverse mortgage originations business. We no longer have any reverse loans remaining in the originations pipeline and have finalized the shutdown of the reverse mortgage originations business. We continue to fund Tails, and, from time to time, securitize these amounts.
As a prior originator of reverse mortgages, this segment received cash proceeds at the time reverse loans were securitized and continues to receive cash proceeds at the time Tails are securitized. We securitized substantially all our reverse loans and continue to securitize Tails through the Ginnie Mae II MBS program into HMBS. Based upon the structure of the Ginnie Mae II MBS program, we determined that these securitizations do not meet all of the requirements for sale accounting, and as such, we account for these transfers as secured borrowings. Under this accounting treatment, the reverse loans remain on our consolidated balance sheets as residential loans. The segment earns net revenue on the net fair value gains on reverse loans and the related HMBS obligations.
This segment also performs subservicing for third-party credit owners of reverse loans, similar to our Servicing segment, and provides other complementary services for the reverse mortgage market, such as real estate owned property management and disposition, for a fee.
Corporate and Other Non-reportable Segment
Our Corporate and Other non-reportable segment includes our corporate functions and also holds the assets and liabilities of the Non-Residual Trusts and corporate debt. Effective January 1, 2018, we no longer allocate corporate overhead, including depreciation and amortization, to our operating segments. These amounts are now included in the Corporate and Other non-reportable segment. Prior year balances have been restated to conform to current year presentation.