Citi Fined Over Deleted Audio of Traders That CFTC Subpoenaed

Citigroup Inc. was fined $4.5 million by the U.S.’s main derivatives regulator over a design flaw that led to the deletion of millions of audio files, including trader recordings that were subpoenaed as part of a federal investigation.

In December 2018, the bank notified the Commodity Futures Trading Commission that it had erased more than 2.77 million audio files, including recordings of traders sought a year earlier by the agency. Citigroup, which didn’t admit or deny the regulator’s findings, had assured CFTC enforcement attorneys they had the recordings in question.

“Registrants have obligations to diligently supervise all aspects of their ...