Always one step ahead of sophisticated systems and the most advanced technology, trader lexis may hold the keys to finding out precisely what rogue market players are really getting up to.
Trader jargon is thick with terms and tales that are impenetrable to any computer decoder, so institutions in the City have gone back to basics and are employing staff to eavesdrop on the banter-laden phone calls as trading takes place.
In its annual market-abuse survey, PriceWaterhouseCoopers drew research from twenty of the biggest world banks that operate in Europe, Africa and the Middle East. The professional services network said: "Banks are steadily expanding the teams tasked with reviewing thousands of flagged messages every day. Teams listening to phone calls are also growing...."
According to the study, banks can have up to 50 staff members listening in on calls and going through emails every day, while the collective spend on surveillance technology in 2016 looks set to hit £156 million.
The latest drive to root out malpractice finds its origins in a brace of heavy scandals within the industry. The Libor and foreign exchange rigging affair racked up fines to the tune of $20bn for brokerages and banks, and led to proposals by the government's Fair and Effective Markets Review which sought to turn over a new ethical leaf in the City.
In the subsequent revision and overhaul of surveillance methods, new and shocking communications were discovered which featured some traders asking for rates to be fixed.
The Financial Conduct Authority has, in the past, been accused of misunderstanding Cockney rhyming slang as evidence of code used for nefarious purposes. An unsuccessful challenge was brought by the watchdog against a former trader at Barclays.
Banks face the daunting task of sifting through countless messages between market operators which, more often than not, will simply be harmless day-to-day correspondence or banter.