Worse still, banks have used swaps to provide complex financial products. They have made swaps in unregulated markets. The buyers had no relationship with the underlying assets. They didn`t understand their risks. When they were late in payment, swap sellers such as Municipal Bond Insurance Association, Ambac Financial Group Inc. and Swiss Reinsurance Co. were hit hard. The sovereign debt crisis in Europe was the result of a combination of complex factors, including the globalization of finance; Simple credit conditions for 2002-2008, which were encouraged to implement high-risk credit and credit practices; the global financial crisis from 2007 to 2012; international trade imbalances; real estate bubbles that have since burst; the global recession from 2008 to 2012; budget decisions related to public revenues and expenditures; and the approaches used by nations to rescue struggling banking industries and private bondholders, shoulder the burden of private debt or socialize losses. The credit risk swap market also shows the beginning of the state crisis. Most CDSs are documented with standard forms designed by the International Association of Swaps and Derivatives (ISDA), although there are many variants.
 In addition to simple single-name swaps, there are basket default swaps (BDS), indexed CDS, financed CDS (also known as credit-related notes) and credit default swaps (LCDS). In addition to companies and governments, the reference unit may include an ad hoc entity issuing debt-backed securities.   Credit risk swaps have become a very popular way to manage this type of risk. The U.S. Comptroller of the Currency publishes a quarterly report on credit derivatives and, in a June 2020 report, estimated the total market size at $4 trillion, including $3.5 trillion for CDS. Given that the market value of CDS is more important than the bonds and credits on which the contract refers, it is clear that speculation is the most common function for a CDS contract. A CDS offers a very effective way to obtain an opinion on the credit of a reference company. Credit risk swaps in their current form have been in place since the early 1990s and were strengthened in the early 2000s. At the end of 2007, the stock of CDS was $62.2 trillion to $26.3 trillion  in mid-2010 and $25.5 billion in early 2012. CDSs are not traded on the stock exchange and there is no necessary reporting of transactions to a government agency.  During the 2007-2010 financial crisis, the lack of transparency in this large market became a problem for regulators, as it could pose a systemic risk.   In March 2010, the Depository Trust – Clearing Corporation (see market data sources) announced that it would give supervisors better access to its credit risk swap database.
 Despite these concerns, credit risk swaps have proven to be a useful tool for portfolio management and speculation and are expected to remain an important and critical part of financial markets.