# Credit Default Swaps (CDS) > 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. Source: https://learn.tradelabsai.com/bonds-credit/credit-default-swaps/ Track: Bonds, Rates and Credit · Level: Advanced · Updated: 2026-10-03 Publisher: TradeLabs AI (https://tradelabsai.com). Education, not financial advice. Cite as: TradeLabs Learn, "Credit Default Swaps (CDS)", https://learn.tradelabsai.com/bonds-credit/credit-default-swaps/ A credit default swap (CDS) is a contract that transfers the credit risk of a borrower from one party to another. The protection buyer pays a regular premium; in return, the protection seller pays out if the reference borrower suffers a credit event such as default or bankruptcy. A CDS works like insurance on a bond, except that buyers do not need to own the bond. CDS became infamous during the 2008 financial crisis, but they remain a major tool for hedging and trading credit risk. ## How a CDS works | Party | Pays | Receives | |---|---|---| | Protection buyer | Quarterly premium (the spread or coupon) | Payment if a credit event occurs | | Protection seller | Payment after a credit event | Premiums while no credit event occurs | After a credit event, the seller compensates the buyer for the loss: roughly the notional amount times (1 minus the recovery rate), usually determined through an industry auction of the defaulted bonds. **Example: Buying protection** A fund owns $10 million of a company's bonds and buys 5 year CDS protection at 250 basis points a year. It pays $250,000 a year (in quarterly instalments). - **No default for 5 years:** the fund pays $1.25 million in total and receives nothing, but it was insured. - **Default in year 2 with 35% recovery:** the seller pays $10 million × (1 minus 0.35) = $6.5 million, offsetting the fund's loss on the bonds. Premiums stop. ## Spreads and upfront payments Modern CDS contracts use standard coupons (for example 100 or 500 basis points a year), with an upfront payment to adjust for the difference between the standard coupon and the market spread. If the market spread is 250 basis points on a contract with a 100 basis point coupon, the buyer pays an upfront amount roughly equal to the present value of the extra 150 basis points a year. ## What CDS spreads tell you CDS spreads give a market based estimate of default risk: ``` annual default probability ≈ CDS spread / (1 - recovery rate) ``` A spread of 300 basis points with 40% recovery implies roughly a 5% annual default probability under risk neutral assumptions. See [Default Probability and Recovery Rate](https://learn.tradelabsai.com/bonds-credit/default-probability/). ## Credit events Standard credit events, defined by ISDA documentation, include: - **Bankruptcy.** - **Failure to pay** after any grace period. - **Restructuring** (for some contracts, such as many European and sovereign CDS). - **Obligation acceleration or repudiation** (mainly for sovereigns). Regional committees of dealers and investors decide whether a credit event has occurred. ## Uses of CDS | Use | Example | |---|---| | Hedging | A bank buys protection on a large borrower | | Speculating on deterioration | Buy protection without owning bonds | | Taking credit exposure | Sell protection instead of buying bonds | | Relative value | Trade the CDS against the bond (the basis) | | Index trading | Trade CDX or iTraxx indices. See [Credit Indices](https://learn.tradelabsai.com/bonds-credit/credit-indices/) | ## CDS and the 2008 crisis AIG sold protection on hundreds of billions of dollars of mortgage linked securities without enough capital to pay. When those securities fell, AIG faced massive collateral calls and needed a government rescue of about $182 billion in commitments. Meanwhile, investors who bought CDS on mortgage securities, as depicted in accounts of the crisis, profited enormously. See [The 2008 Financial Crisis](https://learn.tradelabsai.com/history/the-2008-financial-crisis/). ## Reforms After the crisis, regulators required central clearing for standardised index CDS and many single name contracts, imposed margin requirements and trade reporting, and standardised contract terms (the 2009 "Big Bang" and "Small Bang" protocols). See [Clearing Houses and Central Counterparties](https://learn.tradelabsai.com/market-structure/clearing-houses/). ## Risks - **Counterparty risk:** the seller may fail to pay, as AIG nearly did. - **Jump risk for sellers:** large losses arrive suddenly at default. - **Basis risk:** CDS and bond prices can diverge. - **Liquidity:** many single name CDS are thinly traded. - **Documentation disputes** over what counts as a credit event. ## Frequently asked questions ### What is a credit default swap? A contract in which the protection buyer pays periodic premiums and the seller pays out if a reference borrower defaults or has another credit event. ### Do you need to own the bond to buy CDS? No. Buying CDS without owning the bond, sometimes called naked CDS, is allowed in most markets, though EU rules restrict naked sovereign CDS. ### What role did CDS play in 2008? Large sellers of protection, notably AIG, could not cover losses on mortgage linked CDS, contributing to the crisis and requiring government intervention. Next, learn how default risk is estimated in [Default Probability and Recovery Rate](https://learn.tradelabsai.com/bonds-credit/default-probability/). ## Continue learning - Next lesson: [Default Probability and Recovery Rate](https://learn.tradelabsai.com/bonds-credit/default-probability/) - Previous lesson: [Credit Spreads](https://learn.tradelabsai.com/bonds-credit/credit-spreads/) - Related: [Credit Spreads](https://learn.tradelabsai.com/bonds-credit/credit-spreads/): A credit spread is the extra yield a risky bond pays over a safe benchmark. Learn how spreads are measured, what drives them and what they signal about risk. - Related: [Default Probability and Recovery Rate](https://learn.tradelabsai.com/bonds-credit/default-probability/): Default probability is the chance a borrower fails to pay. Learn historical default rates, probabilities implied by spreads, the Merton model and recovery rates. - Related: [Credit Indices](https://learn.tradelabsai.com/bonds-credit/credit-indices/): Credit indices track baskets of credit default swaps or bonds. Learn how CDX and iTraxx work, rolls, index tranches, bond indices and how traders use them. - 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: [The 2008 Financial Crisis](https://learn.tradelabsai.com/history/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.