A credit default swap index is a credit derivative used to hedge credit risk or to take a position on a basket of credit entities. Unlike a credit default swap, which is an over the counter credit derivative, a credit default swap index is a completely standardised credit security and may therefore be more liquid and trade at a smaller bid-offer spread. This means that it can be cheaper to hedge a portfolio of credit default swaps or bonds with a CDS index than it would be to buy many single name CDS to achieve a similar effect. Credit-default swap indexes are benchmarks for protecting investors owning bonds against default, and traders use them to speculate on changes in credit quality.