They started to list some types of swaps, swaptions and swap futures on their platforms. Derivatives such as credit default swaps (CDSs) were unregulated or barely regulated. For derivatives, these agreements are usually governed by an International Swaps and Derivatives Association agreement. Swaps and Credit derivatives also differ in legal function. Companies can also attempt to hedge translation risk by purchasing currency swaps or futures contracts. Investors can gain exposure to the equity markets using futures, options and swaps. Instruments used include&colon; equities, fixed income, futures, options, and swaps. The vast majority of commodity swaps involve crude oil. Vulture funds also owned a large quantity of credit default swaps (CDS) against Argentine bonds. Pan Asian currency swaps were introduced in the event of another crisis. These "naked credit default swaps" allow traders to speculate on the creditworthiness of reference entities. National banks in the USA used credit default swaps as early as 1996. These are typically termed (single currency) basis swaps (SBSs). This limited the corporation's ability to make acquisitions via stock swaps. There are two competing theories usually advanced for the pricing of credit default swaps.