Over-the-counter trades are trades conducted outside a recognized stock exchange. Leeson claimed that an amount of £50m (outstandingsince December 1994) was due from Spear, Leeds and Kellogg, a reputable broking firm which specialized in derivatives. Barings’ auditors in London, Coopers and Lybrand, needed an explanation for what had happened and also needed to see documentation that would support Leeson’s claim.