# The 2008 Financial Crisis

> The 2008 financial crisis grew from a US housing bubble into a global banking panic. Learn the causes, the collapse of Lehman Brothers, the response and the lessons.

Source: https://learn.tradelabsai.com/history/the-2008-financial-crisis/  
Track: Market History · Level: Beginner · Updated: 2026-10-03  
Publisher: TradeLabs AI (https://tradelabsai.com). Education, not financial advice.  
Cite as: TradeLabs Learn, "The 2008 Financial Crisis", https://learn.tradelabsai.com/history/the-2008-financial-crisis/

The global financial crisis of 2007 to 2009 was the most severe financial crisis since the Great Depression. It began with falling US house prices and rising defaults on subprime mortgages, spread through complex securities held by banks worldwide, and peaked with the bankruptcy of Lehman Brothers in September 2008. Credit markets froze, stock markets fell by more than half, and governments and central banks launched unprecedented rescues. The crisis reshaped banking regulation, monetary policy and how investors think about risk.

## Timeline

| Date | Event |
|---|---|
| 2006 | US house prices peak |
| 2007 | Subprime lenders fail; two Bear Stearns hedge funds collapse; interbank funding markets seize in August |
| 9 October 2007 | The S&P 500 peaks at 1,565.15 |
| March 2008 | Bear Stearns is rescued through a sale to JPMorgan backed by the Federal Reserve |
| September 2008 | Fannie Mae and Freddie Mac are taken into conservatorship (7 September); Lehman Brothers files for bankruptcy (15 September); AIG is rescued (16 September); a money market fund "breaks the buck" |
| October 2008 | Congress passes TARP, authorising $700 billion; global coordinated rate cuts |
| 25 November 2008 | The Fed announces its first large scale asset purchases. See [Quantitative Easing and Tightening](https://learn.tradelabsai.com/macro/quantitative-easing/) |
| 9 March 2009 | The S&P 500 bottoms at 676.53, about 57% below its peak |

## Causes

| Cause | Explanation |
|---|---|
| Housing bubble | Prices rose far above incomes, fuelled by easy credit |
| Subprime and risky lending | Loans to borrowers with weak credit, often with low initial "teaser" rates |
| Securitisation | Mortgages were packaged into securities and complex products such as CDOs, spreading risk widely and weakening lending standards |
| Credit ratings | Many mortgage securities received top ratings that proved far too optimistic. See [Credit Ratings](https://learn.tradelabsai.com/bonds-credit/credit-ratings/) |
| Leverage | Investment banks and others ran very high leverage with short term funding |
| Derivatives | Credit default swaps concentrated exposures at firms such as AIG. See [Credit Default Swaps (CDS)](https://learn.tradelabsai.com/bonds-credit/credit-default-swaps/) |
| Interconnection | Counterparty links meant one failure threatened many. See [Market, Credit and Counterparty Risk](https://learn.tradelabsai.com/portfolio/counterparty-risk/) |

## Why Lehman mattered

Lehman Brothers was a large investment bank heavily exposed to real estate, funded with short term borrowing. When no buyer or government rescue emerged, it filed the largest bankruptcy in US history. Its failure froze client assets, triggered losses for counterparties and money market funds, and caused lenders to pull back from other firms. The crisis shifted from a housing problem to a systemic panic within days. See [Systemic Risk](https://learn.tradelabsai.com/portfolio/systemic-risk/).

**Example: A leveraged balance sheet**
Suppose a bank holds $100 billion of assets funded by $97 billion of borrowing and $3 billion of equity, leverage of about 33 times. If its assets fall in value by just 3%, its equity is wiped out. Major US investment banks ran leverage in roughly this range before the crisis. When mortgage securities fell sharply and lenders refused to roll over short term loans, small asset losses became existential threats. This is why post crisis rules raised capital requirements and limited leverage. See [Leverage](https://learn.tradelabsai.com/markets/leverage/) and [Liquidity Risk](https://learn.tradelabsai.com/portfolio/liquidity-risk/).

## The response

| Response | Detail |
|---|---|
| Rescues and capital injections | TARP funds recapitalised banks; AIG, Fannie Mae and Freddie Mac were rescued |
| Monetary policy | The Fed cut rates to near zero by December 2008 and began quantitative easing |
| Liquidity facilities | Emergency lending to banks, dealers and money markets |
| Stress tests | The 2009 bank stress tests restored confidence. See [Stress Testing and Scenario Analysis](https://learn.tradelabsai.com/portfolio/stress-testing/) |
| Regulation | Dodd Frank Act (2010), Basel III capital and liquidity rules, the Volcker Rule, central clearing of swaps. See [Clearing Houses and Central Counterparties](https://learn.tradelabsai.com/market-structure/clearing-houses/) |

## Lessons

1. **Leverage plus short term funding is fragile.**
2. **Ratings and models can fail together** when assumptions are wrong. See [Operational and Model Risk](https://learn.tradelabsai.com/portfolio/operational-and-model-risk/).
3. **Correlations jump in crises;** diversified risky portfolios fell together. See [Correlation Management](https://learn.tradelabsai.com/portfolio/correlation-management/).
4. **Counterparty risk is real:** know who holds your assets. See [Market, Credit and Counterparty Risk](https://learn.tradelabsai.com/portfolio/counterparty-risk/).
5. **Policy responses can be large and fast,** changing market dynamics.

## Sources

- Federal Reserve History, "The Great Recession and Its Aftermath": https://www.federalreservehistory.org/essays/great-recession-and-its-aftermath

## Frequently asked questions

### What caused the 2008 financial crisis?

A US housing bubble, risky mortgage lending, complex securitisation, flawed credit ratings, high leverage and interconnected financial firms.

### Why did Lehman Brothers fail?

It had large real estate exposures and relied on short term funding; when confidence collapsed, it could not refinance and no rescue was arranged.

### How much did stocks fall in 2008?

The S&P 500 fell about 57% from its October 2007 peak to its March 2009 low.

Next, learn about a crash that took minutes in [The 2010 Flash Crash](https://learn.tradelabsai.com/history/the-2010-flash-crash/).

## Continue learning

- Next lesson: [The 2010 Flash Crash](https://learn.tradelabsai.com/history/the-2010-flash-crash/)
- Previous lesson: [The Dot-Com Bubble](https://learn.tradelabsai.com/history/the-dot-com-bubble/)
- Related: [The Dot-Com Bubble](https://learn.tradelabsai.com/history/the-dot-com-bubble/): The dot com bubble saw internet stocks soar in the late 1990s and the Nasdaq lose about 78% by 2002. Learn the causes, warning signs and lessons for investors.
- Related: [Systemic Risk](https://learn.tradelabsai.com/portfolio/systemic-risk/): Systemic risk is the danger that problems at one firm or market spread through the whole financial system. Learn its channels, past examples and what traders can do.
- Related: [Credit Default Swaps (CDS)](https://learn.tradelabsai.com/bonds-credit/credit-default-swaps/): A credit default swap is insurance like protection against a borrower defaulting. Learn how CDS work, spreads and upfront pricing, credit events, uses and risks.
- Related: [Market, Credit and Counterparty Risk](https://learn.tradelabsai.com/portfolio/counterparty-risk/): Learn the difference between market risk, credit risk and counterparty risk, how each is measured and managed, and real cases from Lehman Brothers to FTX.
- Related: [Quantitative Easing and Tightening](https://learn.tradelabsai.com/macro/quantitative-easing/): Quantitative easing is central bank bond buying to lower long term rates; tightening reverses it. Learn how QE and QT work, their history and market effects.
- Related: [Liquidity Risk](https://learn.tradelabsai.com/portfolio/liquidity-risk/): Liquidity risk is the danger of being unable to trade quickly at a fair price, or running short of cash. Learn its two types, how to measure it and controls.