No financial instrument became more infamous during the 2008 financial crisis than the credit default swap. Blamed by politicians, misunderstood by commentators, and used by both hedgers and speculators, CDS fundamentally changed how credit risk is priced, transferred, and concentrated in the financial system. Understanding CDS is essential not just to understanding derivatives markets, but to understanding how modern banking and credit intermediation work.
How a CDS works mechanically
Suppose a credit fund holds £50 million of bonds issued by a large European retailer. The fund is concerned about deteriorating credit quality but does not want to sell the bonds (triggering tax or disrupting a long-term position). It can buy 5-year CDS protection on that retailer at a spread of 180bps. Each quarter, it pays 45bps × £50m ÷ 4 = £56,250 to the protection seller. If the retailer defaults during the five years and bonds recover 40p on the pound, the protection seller pays the fund £30 million (£50m × 60% loss-given-default). The fund's bond loss is offset by the CDS payout.
CDS spreads as credit market signals
Because CDS can be traded freely without holding the underlying bonds, CDS spreads often move faster and more transparently than bond spreads. When a company's credit quality deteriorates, its CDS spread widens — reflecting the increased cost of protection. Markets watch CDS on major sovereigns and corporates as real-time credit quality indicators. The CDS spread on a company is also sometimes used to imply a probability of default: a 5-year CDS at 300bps on a bond with typical recovery of 40% implies roughly a 5% annual default probability.
Naked CDS: speculation without ownership
Because CDS do not require the buyer to hold the reference bonds, they can be used speculatively: buying protection on a borrower you believe will default (without owning any of their bonds) is sometimes called a "naked" CDS position. Critics argued — particularly during 2008 — that naked CDS created perverse incentives, allowing institutions to profit from defaults without having any economic interest in preventing them. The EU banned naked sovereign CDS on European government bonds in 2012, though the practical impact on liquidity was controversial and the ban has been debated ever since.