MBS — Mortgage Backed Securities
Mortgage-Backed Securities — Structure, Market History, the Agency Framework, and the Regulatory Architecture of the Securitized Mortgage Market
Mortgage-backed securities are fixed-income instruments whose cash flows derive from pools of mortgage loans secured by real property. These securities occupy a central position in the global fixed-income markets and represent one of the largest segments of the asset-backed securities universe. MBS are created through securitization structures in which mortgage loans are transferred to a trust or special purpose vehicle that issues securities backed by the principal and interest payments made by the underlying borrowers. The term MBS is used broadly to encompass both residential mortgage-backed securities and commercial mortgage-backed securities, as well as agency pass-through securities, collateralized mortgage obligations, and other structured instruments backed by mortgage collateral. The market includes securities guaranteed by government-related entities as well as private-label transactions supported solely by the credit quality of the underlying loans and the structural protections embedded in the transaction documents. The U.S. agency MBS market alone had approximately $9.1 trillion in outstanding securities as of late 2024 — Fannie Mae at $3.6 trillion, Freddie Mac at $3.0 trillion, and Ginnie Mae at $2.5 trillion — making it one of the largest single fixed-income markets in the world and a market whose behavior directly determines mortgage rates for American homeowners. The three largest holders of that $9.1 trillion are commercial banks at $2.6 trillion, the Federal Reserve at $2.5 trillion, and foreign investors at $1.3 trillion, reflecting the central role of agency MBS in bank balance sheet management, Federal Reserve monetary policy transmission, and global reserve asset allocation simultaneously.
https://www.fhfa.gov/conservatorship
https://www.sifma.org/research/statistics/us-mortgage-backed-securities-statistics
Corvid Partners maintains recognized expertise in the analysis and valuation of mortgage-backed securities across the full spectrum of agency and non-agency structures, including residential pass-through securities, collateralized mortgage obligations, commercial mortgage securitizations, credit-risk-transfer securities, and distressed legacy transactions. Members of the firm have traded, analyzed, and valued MBS across multiple market cycles, including the rapid expansion of securitization in the 1990s and early 2000s, the severe dislocations of the 2007-2009 financial crisis, the subsequent period of regulatory reform and litigation, and the current market environment characterized by evolving underwriting standards, interest-rate volatility, and increased regulatory oversight. That experience includes direct, desk-level management of legacy mortgage positions at Barclays following the acquisition of Lehman Brothers' U.S. broker-dealer operations in September 2008 — work that required valuing, restructuring, and resolving mortgage-related positions in markets that had ceased to function, at the moment when the interaction between MBS collateral quality, servicer advancing mechanics, and GSE conservatorship dynamics was determining realized losses across the entire securitization system.
The Agency Mortgage-Backed Securities Market — The Three GSEs and the Government Guarantee Framework
The agency mortgage-backed securities market is dominated by securities issued or guaranteed by three government-related entities: the Government National Mortgage Association (Ginnie Mae), the Federal National Mortgage Association (Fannie Mae), and the Federal Home Loan Mortgage Corporation (Freddie Mac). Securities guaranteed by Ginnie Mae carry the explicit full faith and credit guarantee of the United States and are backed by pools of loans insured by federal housing programs — primarily FHA-insured mortgages, which comprised approximately 55.5 percent of Ginnie Mae's outstanding collateral as of November 2024, and VA-guaranteed mortgages, which comprised approximately 40.3 percent. Ginnie Mae is a government corporation within the Department of Housing and Urban Development and does not itself originate or purchase mortgages — it guarantees the timely payment of principal and interest on securities issued by approved private lenders against pools of government-insured loans. This distinction from the GSEs is important: Ginnie Mae's full faith and credit guarantee is explicit and statutory, while Fannie Mae and Freddie Mac operated under an implicit guarantee until the September 2008 conservatorship made that guarantee explicit in practice.
Securities issued or guaranteed by Fannie Mae and Freddie Mac carry guarantees of timely payment of principal and interest provided by those government-sponsored enterprises. Fannie Mae was established under the New Deal in 1938 as a wholly government-owned entity, restructured in 1968 as a privately owned GSE, and together with Freddie Mac — established in 1970 — operated for four decades under an implicit government backstop that the market priced as near-equivalent to explicit federal backing. Between them, the two GSEs had $5.3 trillion of guaranteed mortgage-backed securities and debt outstanding as of September 2008 — equal to the entire publicly held debt of the United States at that time, as FHFA Director James Lockhart noted in congressional testimony. As of December 2024, Fannie Mae and Freddie Mac collectively guaranteed $6.6 trillion in agency MBS, representing approximately 50 percent of all outstanding U.S. mortgage debt.
https://www.fhfa.gov/conservatorship
Agency MBS are commonly issued in pass-through form, in which investors receive a pro-rata share of principal and interest payments from the underlying mortgage pool. The pass-through rate to the investor equals the original mortgage coupon less the servicing fee paid to the entity collecting payments and less the guarantee fee paid to the issuing GSE. More complex structures are created through collateralized mortgage obligations, in which the cash flows from a pool of mortgage loans are divided into multiple tranches with different maturities, coupon structures, and priorities of payment. These structures allow investors to select securities with different levels of prepayment sensitivity, duration, and yield. The TBA — to-be-announced — market, in which agency MBS are bought and sold on a forward basis before the specific pool composition is known, is the mechanism through which the agency MBS market achieves its extraordinary liquidity. In 2024, the TBA market had an average daily trading volume of approximately $290 billion, making it one of the most liquid and transparent financial markets globally. Agency securities generally present minimal credit risk due to the guaranty of the issuing entity, and valuation is therefore driven primarily by interest-rate risk and borrower prepayment behavior.
The September 2008 Conservatorship — The Most Important Event in the Market's Post-War History
On September 6, 2008, the FHFA placed Fannie Mae and Freddie Mac into conservatorship with the consent of each enterprise's board of directors — the most significant government intervention in the U.S. housing finance system since the New Deal. The action was precipitated by the combined GSE losses of $14.9 billion, mounting concerns about their ability to fund themselves with $89 billion in long-term debt maturing in the second half of 2008, and their inability to access capital markets to bolster their capital positions. The FHFA concluded that without government intervention, the only alternative would have been for the GSEs to cease new business and shed assets into a weak market — an outcome that would have been catastrophic both for mortgage rates and for the prices of their own outstanding securities.
https://www.fhfa.gov/conservatorship/history
https://en.wikipedia.org/wiki/Federal_takeover_of_Fannie_Mae_and_Freddie_Mac
The conservatorship was executed through a four-part rescue plan. The Treasury entered into Senior Preferred Stock Purchase Agreements with each GSE, providing a keepwell commitment under which Treasury would purchase enough senior preferred stock to restore positive net worth in any quarter in which the GSE's net worth became negative — initially capped at $100 billion per GSE, later amended. U.S. taxpayers ultimately injected a combined $187.5 billion into Fannie Mae and Freddie Mac between 2008 and 2017. Both GSEs reported annual losses through 2011, returned to profitability in 2012, and have since repaid more than their Treasury draws in dividends — Fannie Mae alone paid $142.5 billion in dividends against $116 billion in Treasury draws as of August 2015. As of 2024, both GSEs remain under conservatorship, building capital reserves toward an eventual exit that has been discussed but not implemented through multiple administrations. The conservatorship eliminated the implicit guarantee ambiguity that had characterized the pre-crisis GSE structure, replacing it with an explicit Treasury backstop that has provided continuous support to the $9.1 trillion agency MBS market for over sixteen years.
https://www.newyorkfed.org/medialibrary/media/research/staff_reports/sr719.pdf
https://www.congress.gov/crs-product/R44525
https://newbagehot.yale.edu/docs/rescue-fannie-mae-and-freddie-mac-module-conservatorships
Credit Risk Transfer — The Most Important Structural Innovation Since the CMO
The most consequential structural development in the agency MBS market since the conservatorship is the credit risk transfer program, established in 2012 by FHFA directive and first implemented through securities issuances in 2013. CRT was the FHFA's response to the fundamental problem exposed by the conservatorship: that under the pre-crisis model, the GSEs securitized mortgages as pass-through certificates and sold only interest-rate risk to investors, retaining 100 percent of mortgage credit risk on their own balance sheets — and therefore on the taxpayer's balance sheet — while the housing market bore all the credit exposure.
https://www.fhfa.gov/sites/default/files/2023-05/CRT-Progress-Report-4Q20.pdf
Freddie Mac brought to market the first securities-issuance CRT in July 2013 — the Structured Agency Credit Risk program — which FHFA's then Acting Director described as a key step in the process of attracting private capital back to the U.S. housing finance market. Fannie Mae's first Connecticut Avenue Securities offering followed in October 2013. In the STACR and CAS structure, the GSE issues notes whose principal payments are tied to the credit performance of a reference pool of securitized mortgages — effectively synthetic notes or derivatives whose cash flows track to the credit risk of the underlying loans without transferring ownership of those loans. A typical transaction involves a reference pool of approximately $18 to $30 billion in unpaid principal balance, with the GSE selling three to four tranches representing an attachment range of approximately 0.10 to 2.75 percent of the pool, retaining the first-loss position, and issuing notes with initial coupons ranging from benchmark plus approximately 230 to 690 basis points depending on tranche seniority and market conditions. From 2013 through the end of 2020, the GSEs transferred a portion of credit risk on approximately $4.1 trillion in single-family loans through CRT, with a total risk-in-force of $137 billion. As of Q4 2025, Fannie Mae's CAS program references approximately $2.3 trillion in unpaid principal balance of single-family mortgage loans. The CRT market has grown to over $50 billion outstanding and references roughly $2 trillion of single-family mortgage loans in the broader $13 trillion U.S. mortgage market.
https://www.americanactionforum.org/insight/credit-risk-transfers-a-primer/
Non-Agency Mortgage-Backed Securities and the Pre-Crisis Private-Label Market
Non-agency mortgage-backed securities, also referred to as private-label MBS, are issued without a government guarantee and may be backed by residential or commercial mortgage loans that do not meet agency eligibility standards. These securities include prime jumbo RMBS, subprime and Alt-A residential securitizations, commercial mortgage-backed securities, and other specialized structures. Credit enhancement in non-agency transactions is typically provided through subordination, excess spread, overcollateralization, reserve accounts, and structural triggers that redirect cash flow to senior tranches if collateral performance deteriorates. Because repayment depends on both borrower performance and collateral value, valuation of non-agency MBS requires detailed credit analysis in addition to interest-rate modeling.
The pre-crisis expansion of the non-agency private-label MBS market — concentrated in the 2005, 2006, and 2007 vintage years — represents the most consequential episode in the history of mortgage securitization and the period whose failures most directly shaped the regulatory framework that governs the market today. Between 2000 and 2007, Wall Street underwrote approximately $2.1 trillion in subprime mortgage-backed securities, with the peak years of 2005 and 2006 producing the most structurally compromised collateral. The top underwriters in those peak years were Lehman Brothers at $106 billion, RBS Greenwich Capital at $99 billion, and Countrywide Securities at $74.5 billion, followed by Morgan Stanley, Merrill Lynch, Bear Stearns, and Goldman Sachs. The largest originator of subprime loans was Countrywide Financial Corporation — the Calabasas, California-based lender that originated at least $97.2 billion in subprime loans from 2005 through 2007 and was acquired by Bank of America in 2008 in a transaction that ultimately cost Bank of America tens of billions in settlements and litigation. Ameriquest Mortgage originated at least $80.6 billion and New Century Financial — which filed for bankruptcy in April 2007 as one of the earliest high-profile collapses of the crisis — originated more than $75.9 billion.
https://en.wikipedia.org/wiki/Subprime_mortgage_crisis
The deterioration in underwriting standards across the 2005 to 2007 vintage years — the expansion of no-documentation loans, stated-income and stated-asset structures, simultaneous second liens, piggyback loans enabling zero-equity purchases, and the migration of interest-only and negative-amortization products to borrowers who could not absorb payment resets — was documented by the Financial Crisis Inquiry Commission and is addressed in detail in the RMBS chapter of this guide. The umbrella point for this chapter is that the private-label MBS market's collapse was the proximate trigger of the 2008 financial crisis and the event that forced the GSE conservatorship, the National Mortgage Settlement, the Dodd-Frank Act risk retention rules, and the fundamental restructuring of the U.S. housing finance regulatory framework.
https://fcic.law.stanford.edu/report
https://www.gao.gov/products/gao-09-739
The Structural Mechanics of an MBS Transaction
The structural mechanics of an MBS transaction involve the transfer of mortgage loans from an originator or aggregator to a bankruptcy-remote trust, which issues multiple classes of securities backed by the cash flows of the underlying loans. Cash flows consist of scheduled principal and interest, voluntary prepayments, involuntary prepayments resulting from default or liquidation, and recoveries on collateral. These amounts are allocated according to a waterfall defined in the governing transaction documents. Senior classes receive priority of payment, while subordinate classes absorb losses in reverse order of seniority. Many transactions include performance triggers, step-down provisions, shifting-interest structures, and other features that can materially affect the distribution of cash flows under different collateral performance scenarios.
https://www.sifma.org/wp-content/uploads/2018/01/MBS_FactSheet.pdf
The shifting-interest mechanism deserves specific attention because it is the structural feature most consequential to recovery values in non-agency transactions. In the first several years following issuance, shifting-interest structures allocate a disproportionate share of prepayments to senior tranches, accelerating the paydown of senior principal and increasing subordination levels to protect against early defaults. Step-down provisions then allow subordinate classes to begin receiving pro-rata prepayment allocations after the shifting-interest period expires — but only if collateral performance triggers have been satisfied. In distressed transactions, trigger failures lock the step-down, preserving the subordination structure and protecting senior holders at the expense of permanently subordinating junior bondholders. Understanding trigger mechanics is the central analytical skill required to evaluate legacy non-agency MBS positions, where the interaction between collateral performance, trigger status, and subordination levels determines the range of possible recovery outcomes.
Prepayment Behavior — The Defining Analytical Challenge of the MBS Market
Prepayment behavior is a defining analytical challenge across the MBS market. Mortgage borrowers typically have the ability to prepay their loans prior to maturity, and the timing of these prepayments depends on interest-rate levels, refinancing availability, housing prices, borrower credit conditions, and other economic factors. Prepayment speeds are commonly expressed using the Conditional Prepayment Rate convention and are modeled using econometric frameworks that incorporate rate incentive, seasoning, burnout, and seasonality. Because prepayments accelerate when interest rates fall and slow when rates rise, mortgage-backed securities exhibit negative convexity — their price sensitivity to interest-rate changes differs from that of traditional bullet-maturity bonds in ways that require explicit option-adjusted valuation rather than standard yield analysis.
https://www.federalreserve.gov/publications/financial-stability-report.htm
At the desk level, negative convexity means that when rates fall and an unhedged MBS portfolio should be gaining value, the accelerating prepayments that accompany falling rates simultaneously shorten the portfolio's duration — reducing the portfolio's sensitivity to further rate declines at exactly the moment when duration extension would be most valuable. This creates the asymmetric price behavior that defines MBS relative to bullet-maturity corporate bonds: upside is capped by prepayment, while downside in a rising-rate environment extends as prepayments slow and average lives extend well beyond original expectations. A 30-year agency MBS trading to a three-year average life under current rate assumptions may extend to an eight-year or ten-year average life if rates rise 200 basis points — a duration extension that produces mark-to-market losses regardless of the underlying credit quality of the loans. Option-adjusted spread analysis calibrated to the yield curve and volatility surface is the standard framework for adjusting MBS valuations for this embedded optionality.
https://www.federalreserve.gov/publications/financial-stability-report.htm
Credit Analysis for Non-Agency MBS
Credit analysis is particularly important for non-agency MBS and for commercial mortgage securitizations, where the ability of borrowers to repay depends on property values, borrower credit quality, and broader economic conditions. Investors evaluate loan-level characteristics such as loan-to-value ratio, debt-service coverage ratio, borrower credit score, documentation type, occupancy status, geographic concentration, and vintage. Default and loss-severity projections are developed using statistical and scenario-based models that incorporate macroeconomic assumptions, historical performance data, and collateral-specific attributes. In distressed transactions, the interaction between default, loss mitigation, and liquidation timing can significantly affect expected cash flows. The vintage year of the underlying loans is the single most important credit variable in non-agency RMBS analysis — 2005 to 2007 vintage subprime and Alt-A pools carried fundamentally different risk profiles from 2003 to 2004 or 2009 to 2012 originations, and treating them as comparable based on headline rating would produce materially incorrect valuations.
https://www.consumerfinance.gov/rules-policy/regulations/1026/
Servicing — The Operational Foundation of MBS Performance
Servicing plays a critical role in the performance of mortgage-backed securities. The master servicer is responsible for collecting payments, advancing funds when required, and administering the mortgage pool in accordance with the servicing standard defined in the transaction documents. When loans become delinquent or require modification, they may be transferred to a special servicer, who has authority to pursue workouts, restructurings, or foreclosure. The servicer's advancing obligation — the requirement to advance scheduled principal and interest to bondholders even when borrowers are not paying — creates a significant liquidity obligation that influences servicer behavior in distress and can affect realized cash flows to MBS investors when servicer financial strength is impaired.
https://www.consumerfinance.gov/rules-policy/regulations/1026/
Servicer conduct, advancing practices, and the allocation of control rights among bondholders became the central legal and operational challenge in the MBS market following the 2007-2009 financial crisis. The robo-signing foreclosure crisis of 2010 — in which it emerged that employees at the nation's largest servicers had been executing foreclosure affidavits without reviewing the underlying documentation, using manufactured signatures and fraudulent notarizations in tens of thousands of cases — produced the largest civil regulatory settlement in U.S. history at that time. The February 2012 National Mortgage Settlement committed Bank of America, JPMorgan Chase, Wells Fargo, Citigroup, and Ally Financial — the five largest mortgage servicers controlling approximately 60 percent of the servicing market — to a combined $25 billion in penalties and consumer relief, including $10 billion in mortgage principal reductions for underwater borrowers, $3.5 billion to states, and approximately $1.5 billion in direct payments to 750,000 borrowers who had been improperly foreclosed upon. Bank of America paid the most of any single servicer at $8.58 billion in homeowner relief obligations. The settlement also imposed comprehensive new servicing standards requiring single-point-of-contact for borrowers, dual-track prohibition preventing servicers from pursuing foreclosure while simultaneously evaluating loan modification applications, and independent monitoring of servicer compliance.
https://en.wikipedia.org/wiki/2010_United_States_foreclosure_crisis
Mortgage servicing standards are affected by federal consumer-protection rules including those adopted by the Consumer Financial Protection Bureau under Regulation X and Regulation Z, which codified post-National Mortgage Settlement servicing practices into binding federal regulatory requirements. The CFPB rules established mandatory error resolution timelines, force-placed insurance protections, loss mitigation procedural requirements, and periodic statement disclosure standards that permanently altered the cost structure and risk profile of mortgage servicing.
https://www.consumerfinance.gov/rules-policy/regulations/1026/
The Regulatory Framework — Dodd-Frank, Regulation AB II, Basel, and NAIC
The regulatory framework governing mortgage-backed securities issuance and trading has evolved significantly since the 2007-2009 financial crisis. The Dodd-Frank Act introduced credit-risk-retention requirements under Section 941, which generally require securitizers to retain not less than five percent of the credit risk of the assets being securitized, subject to specified exemptions including the Qualified Residential Mortgage exemption for loans meeting defined underwriting standards. The Securities and Exchange Commission adopted Regulation AB II, which enhanced disclosure requirements for registered asset-backed securities offerings, including loan-level reporting for mortgage collateral. These reforms were intended to address the misalignment of incentives between originators, sponsors, and investors that contributed to the deterioration in underwriting standards prior to the crisis.
https://www.govinfo.gov/content/pkg/FR-2014-12-24/pdf/2014-29256.pdf
https://www.govinfo.gov/content/pkg/FR-2014-09-24/pdf/2014-21375.pdf
From a capital-adequacy perspective, holdings of mortgage-backed securities are subject to the securitisation framework established by the Basel Committee on Banking Supervision, which defines methodologies for determining risk-weighted assets based on tranche seniority, credit quality, and structural complexity. Bank regulatory capital requirements under Basel III create distinct economic incentives for holding different categories of MBS — agency pass-through securities carry lower risk weights than non-agency subordinated tranches, influencing the structure of bank demand across the capital stack and contributing to the concentration of non-agency subordinated MBS among hedge funds, insurance companies, and other non-bank investors. Insurance companies holding MBS are subject to risk-based capital requirements established by the National Association of Insurance Commissioners, which rely on modeled expected loss rather than external ratings alone — a methodology designed to prevent the rating-arbitrage that produced artificially low capital charges on highly-rated but structurally complex MBS tranches in the pre-crisis period.
https://www.bis.org/bcbs/publ/d303.htm
https://www.bis.org/bcbs/publ/d374.htm
Secondary Market Pricing and OAS Analysis
In the secondary market, mortgage-backed securities trade at spreads that reflect interest-rate risk, expected prepayment behavior, collateral credit quality, structural position, liquidity, and regulatory capital treatment. Agency securities are evaluated using option-adjusted spread analysis calibrated to the yield curve and volatility surface, while non-agency and distressed securities require detailed cash-flow modeling under multiple performance scenarios. OAS is the constant spread over the risk-free rate that equates the market price of a security to the present value of its expected cash flows under a range of interest-rate scenarios, incorporating the embedded prepayment option. A Ginnie Mae 30-year pass-through trading at an OAS of 30 to 40 basis points is priced with a modest spread premium over Treasuries reflecting prepayment risk and liquidity rather than credit risk. A 2006-vintage subprime RMBS mezzanine tranche trading at a deep discount to par may require an OAS analysis that incorporates default and loss-severity scenarios alongside prepayment modeling — a fundamentally different analytical exercise that combines credit and rate models simultaneously. Because mortgage-backed securities combine elements of interest-rate derivatives, credit instruments, and structured finance products, valuation requires the integration of quantitative modeling, legal analysis, and market experience in ways that few conventional fixed-income frameworks fully accommodate.
https://www.federalreserve.gov/publications/financial-stability-report.htm
https://www.sifma.org/research/statistics/us-mortgage-backed-securities-statistics
Conclusion
The mortgage-backed securities market spans from the $9.1 trillion agency pass-through market — backstopped by a government guarantee that became fully explicit on September 6, 2008, when $187.5 billion in Treasury support stabilized Fannie Mae and Freddie Mac and maintained the functioning of a market representing half of all U.S. mortgage debt — to the privately-originated non-agency market whose 2005 to 2007 vintage subprime and Alt-A collateral produced the largest financial crisis since the Great Depression. The credit risk transfer programs launched in 2013, covering $4.1 trillion in single-family loans through 2020 and referencing $2.3 trillion in current unpaid principal balance through Fannie Mae's CAS program alone, represent the market's structural response to the lesson that the pre-crisis model of retaining 100 percent of mortgage credit risk on GSE balance sheets — and therefore on the taxpayer's balance sheet — was fundamentally unsound. The National Mortgage Settlement's $25 billion judgment against the five largest servicers transformed the operational standards of the servicing industry and codified through CFPB regulation what had previously been informal expectations. The Basel III securitisation framework and NAIC risk-based capital rules completed the regulatory architecture by embedding capital incentives that reward sound underwriting and structural transparency rather than ratings arbitrage. Together these developments define the market that practitioners operate in today — which is analytically richer, structurally sounder, and operationally more complex than the pre-crisis market, but no less demanding of the integrated expertise in interest-rate modeling, credit analysis, structural mechanics, servicing behavior, and legal interpretation that has always defined genuine MBS practitioner knowledge.
Corvid Partners approaches mortgage-backed securities from both a legal and capital-markets perspective, considering origination practices, collateral performance, structural protections, servicing conduct, regulatory framework, and secondary-market trading behavior. The firm's experience spans agency pass-through securities, collateralized mortgage obligations, residential and commercial private-label securitizations, credit-risk-transfer structures, and distressed or litigated positions requiring integrated financial and legal analysis — experience forged from the trading desk level through the most consequential MBS dislocations in market history, including the direct management of legacy mortgage positions at Barclays at the height of the financial crisis, where valuation was not an academic exercise but an operational necessity in markets that had ceased to function.
https://www.sifma.org/research/statistics/us-mortgage-backed-securities-statistics
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Government National Mortgage Association (Ginnie Mae)
Federal National Mortgage Association (Fannie Mae)
Federal Home Loan Mortgage Corporation (Freddie Mac)
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https://www.fhfa.gov/conservatorship
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https://www.fhfa.gov/conservatorship/history
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https://www.americanactionforum.org/insight/credit-risk-transfers-a-primer/
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https://en.wikipedia.org/wiki/Subprime_mortgage_crisis
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https://en.wikipedia.org/wiki/2010_United_States_foreclosure_crisis
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https://www.consumerfinance.gov/rules-policy/regulations/1026/
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https://www.govinfo.gov/content/pkg/FR-2014-12-24/pdf/2014-29256.pdf
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https://www.govinfo.gov/content/pkg/FR-2014-09-24/pdf/2014-21375.pdf
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https://www.bis.org/bcbs/publ/d303.htm
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https://www.bis.org/bcbs/publ/d374.htm
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https://www.sifma.org/wp-content/uploads/2018/01/MBS_FactSheet.pdf
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https://www.sifma.org/research/statistics/us-mortgage-backed-securities-statistics
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https://www.ginniemae.gov/data_and_reports/reporting/Documents/global_market_analysis_dec24.pdf.pdf
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