How Lehman Brothers Broke the World: The 2008 Crisis, Explained

Just before one in the morning on 15 September 2008, lawyers filed the papers that killed a firm older than the telephone. Lehman Brothers had been started in 1850 by German immigrants selling cotton in Alabama. It had lived through the American Civil War, two world wars, and the Great Depression. It died in one night. This was the biggest bankruptcy in United States history, with more than 600 billion dollars in assets that suddenly belonged to no one who could keep them going. By morning, staff were carrying cardboard boxes out of the glass tower on Seventh Avenue while every camera in New York filmed them. Within days the shock reached London, Frankfurt, and Tokyo. Within months the whole world was in the worst slump since the 1930s.

Firms go bust all the time, and one investment bank failing, even a big one, should not do that by itself. Lehman was not really the problem. It was the point where a much bigger, mostly hidden structure gave way underneath it. That structure had been built quietly over the previous ten years, and almost no one understood it fully, including the people who made it. To see why one bankruptcy could freeze credit across the planet, you have to trace the chain backwards, from the trading floor down to a single home loan.

It started with a mortgage

At the bottom of it was something ordinary. A family borrowing money to buy a house. A lot of these were subprime loans, given to borrowers with weak credit, little savings, or shaky income during the American housing boom of the mid-2000s. Some had teaser rates that started low and then jumped after two years. Some were written with hardly any proof of what the borrower actually earned.

None of that was mad on its own. It all rested on one belief, so common that it barely felt like a belief at all: that house prices would keep going up, the way they had across the country for as long as anyone could remember. If prices only ever rose, a shaky loan was not really risky. If the borrower stopped paying, the lender could take the house back and sell it for more than the loan was worth. The house itself would cover the debt. On that thinking, lenders got looser and looser across the country, and a huge amount of money went to people who had no way to repay if prices ever stopped rising.

Turning loans into securities

On its own, one risky mortgage is a small, local problem between a bank and a borrower. The crisis came from what Wall Street built to pass that risk around.

Banks bought thousands of mortgages, put them in one big pool, and sold shares of the monthly repayments to investors around the world. These bundles were called collateralised debt obligations, or CDOs. The clever bit that turned out to be deadly was how the pool got cut into layers, called tranches, ranked by who got paid first. Money coming in from homeowners filled the top layer before a single cent reached the bottom one. The senior tranches, first to get paid and last to lose, were treated as very safe, and the credit-rating agencies routinely stamped them AAA, the same top grade given to government bonds.

That rating rested on a belief of its own: that mortgages spread across Florida, California, Ohio, and Nevada would not all go bad at the same time, because a default in one state had little to do with a default in another. As long as the failures stayed scattered and local, the maths held up, and a pile of shaky loans could be turned into securities the whole world was happy to treat as gold. Pension funds, town councils, and foreign banks bought them exactly because they had been told they were boring and safe.

The synthetic layer

Then the market went one step further, and this is the step that turned a bad situation into a dangerous one for everyone. Investors worked out that they did not need to own any real mortgages to bet on them. Using derivatives, which are contracts whose value comes from something else, they could build a synthetic CDO. This was a product that held no real loans at all. It just pointed at a pool of loans and paid out based on how those loans behaved.

That took away the last natural limit on the game. Only so many families live on a street and hold mortgages there. But there is no limit to how many strangers can stand outside and bet on whether those families keep paying. Synthetic products were those side bets, and they let the world's total exposure to American subprime housing grow far bigger than the value of the houses themselves. The real pool of loans might be worth a few billion dollars. The bets piled on top could be worth many times more. Some of these deals were worse than careless. A few were built so that one clever party could bet against the very securities being sold to another party as safe. In effect, they were selling tickets to a fire they quietly expected to start.

Credit default swaps, and the company in the middle

The thing that made all of this work was the credit default swap. Behind the scary name is a simple idea: insurance on a debt. The buyer pays a regular fee, like an insurance premium, and in return the seller promises to pay out in full if the debt goes bad. You could use it for protection, to cover a bond you actually owned, or as a straight bet that someone else's bond would fail, without owning anything at all.

The company that sold these promises on a scale that is hard to believe was AIG, one of the biggest insurers on earth, a household name that also insured planes and skyscrapers. Through a small, barely watched unit in London, AIG wrote credit default swaps covering tens of billions of dollars of mortgage-linked securities. It collected the fees quarter after quarter, and, believing the same thing everyone else did, it treated the chance of ever paying out as near zero. Here was the trap nobody had priced in. Because these contracts were called swaps and not insurance, AIG did not have to set aside the reserves an insurer normally has to keep against a possible claim. It had basically sold fire cover on half a city while keeping almost no water in the tank.

Why the whole thing fell at once

In 2007, American house prices did the one thing the models had treated as almost impossible. They fell across the whole country at the same time, not just in one unlucky town. Every assumption failed at once, in one connected chain. Subprime borrowers could no longer refinance or sell at a profit, so they stopped paying. The mortgage pools stopped paying out, so the securities built on them lost value. The AAA tranches everyone had treated as gold turned out to be nothing of the sort. And the synthetic bets piled on top all came due at the same time.

For AIG, every downgrade and every drop in value set off a clause in its contracts that demanded it post collateral, meaning cash handed over to reassure the other side that it could still pay. The demands came in the billions, then the tens of billions, and AIG did not have the money. Lehman had loaded up on the same mortgage assets and paid for them with short-term loans that had to be renewed almost every day. Its end came when lenders refused to roll those loans over. A bank that has to borrow every morning to survive cannot survive the morning when no one will lend.

Six months earlier, in March, the Federal Reserve had helped push through the emergency sale of the failing bank Bear Stearns to JPMorgan Chase, backing it with a 30 billion dollar loan. Wall Street had started to assume the government would always catch the next firm to fall. This time, over a frantic weekend of talks with no buyer willing to step in without help, and no help on offer, Lehman was left to fail.

That choice broke the trust the whole system runs on. If Lehman could be allowed to fail, then no firm was truly too big to fail, and no one knew who would be next, or who quietly owed money to whom through the huge, hidden web of swaps. Banks stopped lending to each other, even overnight, even for a few hours, because no lender could be sure the borrower would still be around by lunchtime. The market for short-term funding that the entire modern economy relies on began to lock up. The very next day, the Federal Reserve went back on its own logic. It decided it could not let AIG fail too, because if AIG went down it would take with it every bank it had promised to insure, all at once, everywhere. It threw the insurer a lifeline of 85 billion dollars, a number that would eventually grow to about 182 billion.

Why it became the world's problem

None of this stayed inside America, because the securities never had. Banks and funds from Edinburgh to Singapore had bought the same mortgage bonds and traded the same swaps, all of it sold to them as safe, reliable, AAA. When the securities collapsed, the losses were global from day one, and so was the fear that came with them.

Modern banks do not sit on piles of cash. They pay for themselves by borrowing constantly and hugely from one another, which means a loss of trust spreads faster than any loss of money. Once bankers stopped believing they would be paid back, credit froze everywhere at once, not just in New York. Businesses could not roll over the ordinary loans that cover wages. Households could not borrow. Trade finance, the lending that keeps goods moving across oceans, tightened up. A failure that started with cheap mortgages in American suburbs turned into a worldwide recession that wiped out tens of millions of jobs and, in some countries, a decade of growth.

One mistake, all the way up

Underneath all the jargon, the crisis of 2008 was one mistake made with a straight face at every level. Risky loans were treated as safe. Securities built out of those risky loans were treated as safe. Insurance sold against those securities was treated as almost free. At each level, the people involved assumed the risk had been passed to someone cleverer, a step up or a step down. The whole thing balanced on one shared belief: that house prices would not fall together across the whole country.

They fell together across the whole country. The system had been built to protect itself against every danger except that one, so when the floor gave way there was nothing under it. Lehman Brothers was not the cause. It was the spot where the ground gave way first, and that is why its name, rather than any of a dozen others, became shorthand for the moment the modern financial world nearly ended. The lesson has lasted longer than the wreckage. Being complicated is not the same as being safe, and a risk that everyone has quietly passed to everyone else has not gone away. It has just been hidden, and gathered up, and made bigger.

Sources

• Federal Reserve History, "Lehman Brothers Bankruptcy".
• Federal Reserve History, "Support for Specific Institutions" (on the AIG rescue).
• Congressional Research Service, "Government Assistance for AIG: Summary and Cost".
• Financial Crisis Inquiry Commission, "The Financial Crisis Inquiry Report".
• Encyclopaedia Britannica, "Bankruptcy of Lehman Brothers".