International derivatives marketplace CME Group today posted a notice of disciplinary action against Telesto Sciences LLC, a proprietary trading firm located in the United States.

Pursuant to an offer of settlement in which Telesto neither admitted nor denied the rule violations or factual findings upon which the penalty is based, on July 22, 2026, a Panel of the New York Mercantile Exchange Business Conduct Committee found that during the time period from June 28, 2022, through October 11, 2023, Telesto’s automated trading system (ATS) engaged in a pattern of

entering a large number of Mass Action Cancel messages across multiple Session IDs in E-mini S&P 500 (ES) futures.

These mass cancels caused a Globex match engine delay, and Telesto immediately followed these messages with aggressive orders that traded ES futures and, in many instances, other equity futures (E-micro S&P, E-micro and E-mini Nasdaq-100, E-mini and E-micro Russell 2000 Index, and E-mini and E-micro Dow Jones Industrial Average Index) microseconds later.

In close succession and subsequent to this described pattern, Telesto’s ATS then liquidated these positions via one or more iceberg orders and aggressor Fill-and-Kill (FAK) orders in ES and other equity futures.

Despite receiving notice of its disruptive messaging activity, Telesto continued to allow its ATS to operate for nearly one year without corrective action, which demonstrated a reckless disregard for the adverse impact on the orderly conduct of trading or the fair execution of transactions.

As a result of this messaging activity, Telesto realized a profit of $310,530.

The Panel concluded that Telesto thereby violated CME Rules 575.C.2. And 575.D.

In accordance with the settlement offer, the Panel ordered Telesto to pay a fine to the Exchange in the amount of $125,000 and disgorge profits in the amount of $310,530.

The effective date of the notice is July 24, 2026.