International derivatives marketplace CME Group has posted a notice of disciplinary action against Tower Research Capital Investments LLC. Pursuant to an offer of settlement in which Tower neither admitted nor denied the rule violations, a Panel of the Chicago Board of Trade (CBOT) Business Conduct Committee found that on October 14, 2021, a trader at Tower made a change to an automated trading system (ATS) without testing the potential impact of the change on the ATS. This change resulted in the ATS incorrectly interpreting the risk associated with a position acquired on another market that delivered market data in notional size rather than contract size. In particular, the ATS interpreted the notional size of the position as the contract size of the position, which resulted in the ATS overestimating the value of the position. This resulted in the ATS submitting a series of fill-and-kill (FAK) orders in the December 2021 2-Year Treasury Note futures market to hedge its incorrectly calculated position.