With this sort of contract, the owner of a big, highly appreciated stock position gets an upfront payment from an investment firm--typically for 75% to 85% of the value of his shares--in exchange for agreeing to deliver a variable number of shares or cash in the future, with the exact amount dependent on how the stock performs.
"That was a group of people who had a good track record of payment and pretty low level of arrears, thrust into a position where they are now is significant arrears, " said Mr Forbes.