On Sunday, a statement issued by the Frankfurt-based lender called the latest charges "regrettable" and said it "sincerely regrets the impact on the Kospi market of an indexarbitrage position unwind involving a small number of Deutsche Bank Group employees".
Nick Leeson told everyone he was doing pure arbitrage: in his case between futures contracts on the Nikkei (the Japanese stock market index) and the Nikkei itself.