The only legitimate purpose of program-trading is in index arbitrage, which was originally its only activity.

FORBES: Program Trading Needs To Be Banned

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 index arbitrage position unwind involving a small number of Deutsche Bank Group employees".

BBC: Deutsche Bank charged in South Korea over stock rout

As the majority were passive investors the electoral equivalent of stockmarket-index investors the small elite of informed active traders were able to arbitrage away the price impact of blind party loyalty.

ECONOMIST: Economics focus

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.

FORBES: Kweku Adoboli: How Did He Lose UBS $2 Billion?