In 2005, America’s housing market seemed unstoppable. Home prices had risen for years, mortgage lending was booming, and Wall Street was making enormous profits by packaging home loans into securities and selling them to investors worldwide. Yet a small group of investors was examining those same securities and reaching a radically different conclusion: the American housing market was sitting on a financial disaster.
Rather than simply warning that house prices would fall, these investors found ways to make money when mortgage securities collapsed. They committed billions of dollars to positions that initially seemed irrational, endured intense financial pressure, and eventually earned extraordinary profits as the housing crisis unfolded.
Their story became famous through Michael Lewis’s bestselling book The Big Short and its 2015 film adaptation. But the real history extends beyond the movie’s central characters. It includes Michael Burry, Greg Lippmann, Steve Eisman, Cornwall Capital, and John Paulson, whose enormous bet became one of the most profitable trades in financial history. Understanding how they succeeded reveals not only their investment strategies but also the weaknesses of the financial system they were betting against.
Why Wall Street Thought Housing Could Not Fail
During the early 2000s, American banks and mortgage lenders increasingly extended housing loans to borrowers with weak credit histories, unstable incomes, or limited savings. These subprime mortgages often carried attractive introductory interest rates that made their initial payments manageable. After a few years, however, the rates could reset substantially higher, leaving borrowers facing monthly payments they might struggle to afford.
This lending boom was sustained by a financial process called securitization. Instead of retaining mortgages and collecting payments over decades, lenders could sell loans to financial institutions that pooled thousands of them into residential mortgage-backed securities (RMBS). Investors purchased claims on the payments from these mortgage pools, while banks and other intermediaries earned fees by creating, structuring, and distributing the securities.
The mortgage pools were divided into different layers, known as tranches, that absorbed losses in a particular order. Senior tranches received payments first and were protected by subordinate tranches that would absorb initial losses. Credit-rating agencies assigned high ratings to many senior securities, encouraging the belief that even mortgages issued to risky borrowers could become relatively safe investments when appropriately packaged.
The arrangement depended heavily on assumptions about housing prices and borrower behavior. Rising property values allowed struggling homeowners to refinance or sell their homes before payment difficulties became severe. But if prices stopped climbing, refinancing would become harder, defaults could increase, and the lower-rated portions of mortgage securities could suffer devastating losses.
As the US Senate’s investigation into the financial crisis later documented, the financial industry had developed extensive mechanisms for creating, marketing, and trading mortgage-related products while accumulating risks that were poorly understood or inadequately controlled.
Most market participants did not expect a nationwide housing downturn severe enough to threaten the system. For a few investors willing to examine the underlying mortgages rather than relying on prevailing confidence, however, the potential losses were becoming increasingly apparent.
Michael Burry’s Billion-Dollar Warning
Michael Burry approached Wall Street from an unusual background. Trained as a physician, he had developed an interest in investing while working in medicine, publishing detailed stock analysis on internet discussion boards during the late 1990s. His research eventually attracted investors, and he founded Scion Capital in 2000.
Burry was a value investor who preferred examining financial statements and underlying assets to following market sentiment. When he turned his attention to mortgage-backed securities, he applied the same method: studying the detailed documentation behind individual mortgage pools rather than accepting their credit ratings or the assumptions of the broader market.
He discovered that lending standards had deteriorated dramatically. Mortgage pools increasingly contained interest-only loans, adjustable-rate mortgages, loans made with limited income documentation, and borrowing arrangements that depended on continuing house-price appreciation. These features were particularly dangerous because borrowers who appeared capable of meeting their initial payments could become financially vulnerable once introductory terms expired.
Burry concluded that defaults would begin increasing significantly around 2007, when many adjustable-rate mortgages were scheduled to reset. His analysis went beyond predicting a decline in property prices. He identified particular mortgage bonds whose underlying loans appeared much riskier than the market prices suggested.
The difficulty was finding a practical way to bet against them. Unlike ordinary shares, mortgage bonds could not easily be borrowed and sold short. Burry therefore approached major Wall Street dealers, including Deutsche Bank and Goldman Sachs, seeking credit-default swaps tied to specific subprime mortgage securities.
A credit-default swap, or CDS, is a derivative contract that allows one party to purchase protection against specified credit losses. The protection buyer pays premiums, while the seller assumes an obligation linked to losses or other defined credit events affecting the referenced security. Although frequently compared to insurance, credit-default swaps are tradable financial contracts and do not necessarily require the buyer to own the underlying asset.
For Burry, the appeal was straightforward. If he purchased protection on a mortgage bond that subsequently deteriorated, the swap could become substantially more valuable. If the mortgages remained healthy, he would continue paying premiums and potentially lose the money committed to the position.
In a 2011 lecture at Vanderbilt University, Burry explained that Scion negotiated its first mortgage-related swaps with Deutsche Bank in May 2005 and executed the initial transactions in June. He ultimately established positions through nine dealer counterparties, including Goldman Sachs.
By the time his strategy was fully established, Scion had approximately $1.8 billion in notional CDS exposure to residential mortgage-backed securities. Burry also held roughly $6.6 billion in separate corporate-credit short positions, including exposure linked to financial companies vulnerable to the housing downturn. These were distinct categories of trades and should not be confused with a single $8 billion bet against mortgage bonds.
As Michael Lewis documented in his account of Burry’s strategy, the investment appeared deeply unconventional because the market had not yet begun seriously questioning the value of the securities Burry was targeting.
The banks were willing to take the other side of his trades because they generally considered large-scale mortgage losses unlikely. Burry believed the contracts were relatively inexpensive compared with the losses that could eventually occur. His challenge was no longer identifying the opportunity but maintaining the positions until the anticipated deterioration became visible to the market.
Greg Lippmann and Steve Eisman Follow the Evidence
Burry was not the only investor examining the weaknesses in subprime mortgage securities. Inside Deutsche Bank, mortgage trader Greg Lippmann was developing his own substantial position against the market. Unlike Burry, Lippmann operated directly within the Wall Street system and understood how financial institutions created, distributed, and traded mortgage-related products.
Working with quantitative analyst Eugene Xu, Lippmann studied the performance and structure of subprime mortgage bonds. He concluded that protection against the riskiest portions of these securities could be purchased at prices that did not adequately reflect their likelihood of suffering losses.
Lippmann began promoting the trade to hedge funds and institutional investors, explaining why securities that appeared highly profitable and relatively secure could become nearly worthless if mortgage defaults increased. His position made him an unusual figure: a Wall Street insider encouraging investors to bet against a market that Wall Street itself had helped build.
His activities also illustrated the contradictions within major financial institutions. Deutsche Bank developed substantial short positions in subprime mortgage securities while retaining other mortgage-related investments that remained vulnerable to the downturn. The Senate’s subsequent investigation found that gains from some of the bank’s bearish positions were outweighed by losses elsewhere in its mortgage business.
One investor receptive to Lippmann’s argument was Steve Eisman, a portfolio manager at FrontPoint Partners, which operated within the Morgan Stanley investment-management structure.
Eisman had encountered subprime mortgage lending during the 1990s, when he analyzed companies extending credit to financially vulnerable borrowers. He had watched an earlier generation of subprime lenders encounter severe difficulties in 1998. When similar lending practices reappeared during the housing boom, he recognized familiar warning signs.
His concerns were reinforced by the deteriorating quality of mortgage underwriting. Lenders increasingly approved borrowers using inadequate income verification, optimistic property valuations, and loan structures that depended on refinancing. The incentive to originate more mortgages could outweigh the incentive to ensure borrowers would eventually repay them.
As described in a Harvard Law School account of Eisman’s experience, he understood the industry’s weaknesses partly because he had studied its earlier failures. FrontPoint’s team also investigated lending practices directly, including in Florida, where mortgage brokers and borrowers described arrangements that exposed the dangers underlying the securities.
Eisman and his colleagues eventually purchased credit-default swap protection against subprime mortgage investments. Their decision was based not merely on expectations that property prices would decline but on their conclusion that the securities had been constructed using seriously flawed lending assumptions.
Burry had identified the problem through detailed analysis of individual mortgage pools, while Lippmann approached it through his understanding of trading markets and Eisman through his knowledge of lending businesses. Their different backgrounds led them toward similar positions, even as much of Wall Street continued treating the mortgage boom as a source of reliable profits.
Cornwall Capital Bets on the Unthinkable
Among the investors who recognized the opportunity, Cornwall Capital had one of the most improbable backgrounds. Jamie Mai and Charlie Ledley established the firm in 2003, beginning with approximately $110,000 in a brokerage account and working from a modest office rather than a major financial institution.
Their investing approach differed from that of conventional hedge funds. Instead of trying to predict small fluctuations in asset prices, they searched for situations in which markets assigned extremely low probabilities to events that they considered substantially more likely.
The attraction was an asymmetric payoff. An investment might have a limited upfront cost but deliver an enormous gain if an unlikely scenario occurred. Cornwall’s founders believed that financial markets sometimes underestimated extreme outcomes because investors had become excessively confident in conventional expectations.
When they encountered the case for shorting subprime mortgage securities, it resembled precisely the kind of opportunity they sought. Credit-default swap protection on vulnerable bonds appeared inexpensive relative to the losses that could occur if the housing market deteriorated. They did not have to predict exactly how every mortgage would perform; they needed the prices of their chosen contracts to underestimate the seriousness of the underlying risk.
However, recognizing the trade was easier than gaining access to it. Credit-default swaps were primarily institutional products, and major banks generally required counterparties to satisfy financial and contractual standards before allowing them to trade.
Cornwall lacked the scale and relationships typically needed to establish an International Swaps and Derivatives Association master agreement, the standard contractual framework governing many derivatives transactions. The firm therefore enlisted Ben Hockett, an experienced former securities trader whose industry connections helped it obtain access.
Cornwall’s participation revealed another weakness in the market’s assumptions. Sophisticated institutions were willing to sell relatively cheap protection because they considered severe mortgage losses remote, while a much smaller firm recognized that the potential payoff might justify the premium.
Yet an asymmetric investment was not a risk-free investment. Cornwall could lose the premiums committed to its positions, and the contracts would provide little value unless the market eventually recognized the deterioration. Like the other short sellers, its founders had to confront the possibility that their analysis could be correct while their investment failed because of timing, liquidity, or counterparty problems.
John Paulson Goes Bigger Than Everyone Else
While Burry, Eisman, and Cornwall would become closely associated with The Big Short, another hedge-fund manager was building a position that would produce even larger financial gains.
John Paulson had spent much of his investment career specializing in mergers, acquisitions, and other corporate events. His firm, Paulson & Co., was not initially identified with housing-market speculation. The opportunity emerged through research conducted by his analyst Paolo Pellegrini.
Pellegrini examined historical relationships between American housing prices, household incomes, and broader economic fundamentals. His analysis showed that inflation-adjusted home prices had risen far beyond their traditional relationship with incomes. The divergence suggested that increasingly generous mortgage credit, rather than corresponding improvements in household purchasing power, was helping sustain the boom.
Paulson concluded that a substantial housing correction was likely and that securities tied to the weakest mortgages were especially vulnerable. He began using credit-default swaps to purchase protection against subprime mortgage bonds, constructing positions that could deliver enormous gains if defaults rose and mortgage securities declined in value.
The scale of his strategy distinguished it from many of the other investors’ trades. At its height, Paulson’s firm reportedly held protection referencing roughly $25 billion in subprime mortgage securities. The positions required substantial annual premium payments, reportedly reaching hundreds of millions of dollars.
Such costs created considerable exposure to timing. Even if Paulson correctly anticipated the eventual decline, the firm could lose large amounts of money while the housing market remained strong and mortgage securities retained their perceived value.
Paulson nevertheless saw the unusually favorable relationship between the cost of protection and the potential losses embedded in mortgage securities. As Gregory Zuckerman explains in The Greatest Trade Ever, the strategy combined Pellegrini’s analysis of the housing bubble with an aggressive effort to identify and exploit mispriced mortgage credit.
His approach also differed from Burry’s in its institutional resources and scale. Paulson could commit far more capital, establish extensive relationships with major counterparties, and take positions across numerous securities. What began as an analysis of overvalued housing ultimately became one of the largest coordinated bets against subprime mortgage credit.
Yet Paulson’s enormous potential profits carried an additional complication. Some of the securities connected to his bearish positions would later become central to a major controversy over how complex mortgage investments were assembled and marketed.
The Cost of Being Right Too Early
Predicting a financial collapse and profiting from it are fundamentally different achievements. An investor can identify a serious weakness in a market, establish a position that would benefit from its correction, and still lose money if the market takes too long to recognize the problem.
Credit-default swaps made this challenge especially severe because protection buyers faced continuing premium obligations. A trader could spend millions maintaining positions against mortgage securities that appeared stable, even while the loans supporting those securities were becoming increasingly dangerous.
For Burry, the waiting period became a financial and professional crisis. Through 2006, housing prices and mortgage-related market valuations failed to reflect the losses he expected. Some underlying mortgages were already showing signs of deterioration, but the prices assigned to the related credit-default swaps did not respond as he believed they should.
Burry also faced difficulties with the banks responsible for valuing his derivatives positions. In his Vanderbilt account, he described disputes over the prices quoted by counterparties, which he believed were inconsistent with worsening mortgage fundamentals. These disputes were particularly troubling because a hedge fund’s reported performance depended partly on how its positions were valued.
Scion’s disappointing reported results intensified pressure from investors. Some questioned Burry’s judgment, while others demanded the return of their money or threatened legal action. From their perspective, the fund was losing value while Burry remained committed to a strategy that appeared increasingly speculative.
The situation eventually became so serious that Burry restricted withdrawals from the mortgage-related positions to prevent forced liquidation. He also reduced costs and sold substantial corporate-credit short positions under unfavorable conditions. These decisions helped preserve the mortgage trades but damaged relationships with investors who believed they should have greater control over their capital.
The difficulties highlighted a problem frequently overlooked in stories about successful market predictions. Even a fundamentally sound position can become unsustainable if investors withdraw money, financing becomes unavailable, or counterparties refuse to offer reasonable prices. The market does not have to prove an investment thesis wrong to force an investor out of the trade.
Cornwall Capital faced similar uncertainty on a different scale. Its founders had committed themselves to positions that appeared attractive mathematically but depended on an extraordinarily damaging financial event. As the possible scale of the housing collapse became clearer, the consequences extended far beyond whether their firm would earn a profit.
Paulson faced the same timing problem with much larger financial commitments. His firm’s substantial premium obligations meant that maintaining its bearish positions required confidence, liquidity, and the willingness to tolerate losses before the expected downturn.
Another risk emerged from the structure of credit-default swaps themselves. A successful protection buyer depended on a counterparty capable of meeting its obligations or agreeing to unwind the contract. If the housing market deteriorated so severely that major financial institutions failed, the value of an otherwise successful trade could be threatened by the inability of counterparties to pay.
These pressures explain why the outcome was far from inevitable. Identifying the vulnerability in subprime mortgages was essential, but the investors also needed contracts that would respond to the anticipated losses, sufficient capital to carry the positions, and a practical way to realize their gains.
When the Short Finally Paid Off
The deterioration Burry and the other investors had anticipated became increasingly visible in 2007. Borrowers who had received adjustable-rate or otherwise unsustainable mortgages began falling behind on payments, while declining property values made refinancing and selling homes more difficult.
As defaults increased, investors began reconsidering the assumptions used to value mortgage-backed securities. The market prices of vulnerable bonds fell, and the cost of purchasing protection against mortgage losses rose sharply. Credit-default swaps that had previously seemed inexpensive became much more valuable.
The repricing accelerated during 2007 as the problems spread through mortgage securities and related investment funds. By midyear, serious difficulties at hedge funds exposed to subprime mortgages demonstrated that the losses were no longer a theoretical possibility. The market was beginning to recognize the weaknesses that the short sellers had identified much earlier.
Burry’s retained positions increased dramatically in value. Scion Capital generated substantial gains for its investors, and Burry’s broader investment record became extraordinary. By June 2008, the fund had produced a cumulative net return of approximately 489% since its inception in November 2000.
That figure is important but frequently misunderstood. It represents Scion’s overall cumulative investment performance across several years, not a 489% return on one housing-market trade. The mortgage-related positions were exceptionally profitable, but they formed part of a wider investment history.
Steve Eisman’s FrontPoint team also earned significant gains from its bearish mortgage positions. The fund’s assets reportedly grew from approximately $700 million to around $1.5 billion during the period, although the change in assets should not be confused with an exact measure of profits from credit-default swaps alone.
Cornwall Capital’s investments proved immensely successful as well. The firm that had begun with approximately $110,000 eventually controlled more than $100 million, often described as reaching roughly $120 million. This expansion reflected its broader investment performance over several years, with the mortgage-related trades becoming a defining part of its success rather than accounting for every dollar of growth.
John Paulson achieved the largest headline gains. In 2007, his firm’s mortgage-related strategy generated approximately $15 billion in profits, while one of its major funds returned roughly 590%. Paulson personally earned an estimated $3.7 billion that year, a figure distinct from the profits generated for the firm’s investors.
These gains were realized largely through the repricing and unwinding of derivatives positions as mortgage credit deteriorated. The investors did not necessarily have to wait for every underlying mortgage to default or for the financial system to reach its most dramatic crisis point in September 2008.
Their profits also did not represent money collected directly from homeowners losing their properties. The contractual payments and trading gains occurred within financial markets, primarily among banks, funds, and other counterparties. The underlying reason those contracts became valuable, however, was the escalating failure of mortgage loans and the enormous financial losses associated with them.
The short sellers had correctly identified weaknesses that the market had severely underestimated. But the magnitude of their success exposed a more troubling question: how could securities carrying such serious risks have been created, sold, and valued so confidently in the first place?
The Abacus Scandal and the Price of Winning
John Paulson’s extraordinary profits became particularly controversial because of his involvement in a financial product created by Goldman Sachs called ABACUS 2007-AC1.
ABACUS was a synthetic collateralized debt obligation, or synthetic CDO. Unlike an ordinary mortgage security that receives payments from an actual pool of home loans, a synthetic CDO uses credit derivatives to create exposure to the performance of referenced mortgage securities. This structure allows investors to take opposing positions on mortgage credit risk without necessarily owning the underlying bonds.
Such arrangements could multiply financial exposure to mortgage losses. The same underlying mortgage securities could support additional contractual bets, increasing the potential gains and losses associated with their performance.
In 2007, Paulson & Co. worked with Goldman Sachs on the development of ABACUS while seeking exposure that would profit if the referenced mortgage securities deteriorated. Paulson’s firm participated in discussions concerning the securities included in the transaction and ultimately took a position that would benefit from their declining performance.
Other investors, meanwhile, took the opposite side of the trade. They would benefit if the referenced mortgage securities performed adequately but could suffer substantial losses if the underlying credit deteriorated.
The central controversy concerned what those investors were told about Paulson’s involvement.
In April 2010, the US Securities and Exchange Commission charged Goldman Sachs and one of its employees with securities fraud related to the marketing of ABACUS. The SEC alleged that Goldman had failed to disclose important information about the role of a hedge fund with an economic interest in the transaction’s failure when the reference portfolio was being selected.
The SEC’s case focused on the potential conflict between Paulson’s participation in the selection process and his intention to profit from the deterioration of the selected securities. The agency alleged that the omitted information was material to investors evaluating the transaction.
Goldman Sachs subsequently agreed to pay $550 million to settle the charges. In its official announcement of the ABACUS settlement, the SEC described the resolution and Goldman’s acknowledgment that its marketing materials contained incomplete information.
Paulson himself was not charged in the SEC’s ABACUS case. His participation in the transaction and his financial interest in its failure are therefore distinct from the legal allegations and settlement involving Goldman Sachs. The settlement should not be presented as a finding that Paulson had personally committed securities fraud.
The controversy nevertheless revealed serious problems in how complex financial products were constructed and marketed. A financial institution could help arrange a transaction that allowed one sophisticated investor to profit from mortgage losses while selling the corresponding exposure to other investors whose understanding of the transaction might be incomplete.
This raised questions about conflicts of interest, transparency, and the responsibilities of intermediaries operating in markets where the underlying risks were difficult to evaluate.
The broader history also complicates the idea that the short sellers were simply heroes who recognized what everyone else ignored. Some were motivated by the opportunity to correct obvious market mispricing, others by the possibility of exceptional financial returns, and many combined both considerations. Identifying a dangerously overvalued security did not automatically make an investor altruistic, just as betting against it did not automatically make that investor responsible for the losses eventually suffered by others.
The effects of the housing collapse extended far beyond the institutions trading mortgage derivatives. Foreclosures displaced families, financial institutions failed or required extraordinary assistance, and the ensuing recession destroyed millions of jobs and substantial household wealth. The US Treasury’s historical assessment of the crisis describes the extraordinary economic damage and the response required to stabilize the financial system.
The short sellers’ success must be understood against those consequences. Their trades were profitable because the mortgage securities they targeted were much riskier than prevailing prices suggested. The underlying collapse, however, was a social and economic disaster for people who had never participated in the derivatives market.
It would also be misleading to conclude that only the investors featured in The Big Short anticipated the housing crisis. Economists, analysts, policymakers, and other observers raised concerns about house prices, lending standards, and financial instability before the collapse. What distinguished the featured investors was their ability and willingness to construct substantial financial positions that benefited from a particular failure of mortgage credit.
Ultimately, the real story of The Big Short is about more than identifying a housing bubble. It is about the financial machinery that allowed severe credit risks to be underestimated, transformed into apparently attractive investments, and distributed throughout the banking system.
Michael Burry, Greg Lippmann, Steve Eisman, Cornwall Capital, and John Paulson approached that machinery from different backgrounds and with different resources. They recognized important weaknesses, devised ways to profit from them, and endured the financial uncertainty that came with challenging prevailing market expectations.
Their achievement was not simply predicting that house prices would fall. It was identifying securities whose risks had been mispriced, finding contracts that would benefit from their deterioration, and maintaining those positions until the market recognized the losses.
The extraordinary profits that followed demonstrated the value of independent scrutiny and the dangers of institutional complacency. But they also exposed a financial system in which investors could earn billions by taking the opposite side of risks that major institutions had repeatedly underestimated. The lasting significance of The Big Short lies in that contradiction: the same market that rewarded a few investors for recognizing danger had failed to protect the millions of people who would ultimately bear the consequences.
Last Updated on October 30, 2026 by Aseem Gupta