Chicago’s Old-School Traders Take CME to Court Over Electronic Trading Dominance

Fists fly in finance as pit traders battle algorithms in high-stakes legal showdown.

Open outcry vs. silicon supremacy: The CME faces its ghosts of trading past.

Chicago's floor veterans claim rigged game—while quants count their billions.

Bonus jab: Somewhere, a Goldman algo just shorted justice.

Judge rules in favor of jury trial

According to court filings, the plaintiffs, holding certified classes of Class B shareholders in CME Group and certain members of its CBOT subsidiary, allege that it went against membership privileges, including reduced trading fees and exclusive access to certain trading functions. 

The lawsuit states that in some instances, non-members using the Aurora system were charged lower fees than members, eliminating one of the financial incentives that came with a membership.

Judge Sherlock denied CME’s request to dismiss the case in an April 15 order, ruling that the plaintiffs had substantial legal and factual questions. “

“The Court found an issue of disputed fact concerning almost every point defendants made in their brief in support of summary judgment,” Sherlock wrote. He admitted that CME “certainly has a defensible case” but concluded that a jury must decide the outcome.

CME could lose over $1 billion in damages if the jury deems the platform guilty. Attorney Steve Morrissey of Susman Godfrey, who represents the plaintiffs, said it has attempted to delay the case. “They tried to get it dismissed several times, anything they could do to kick the can down the road,” he remarked. 

Members claim loss of value and rights

In 2007, when CME acquired CBOT, memberships were valued at more than $1 million. Today, they’re worth significantly less. On April 2, 2025, a CME membership last sold for $700,000, a decline from the $1.5 million they reached in 2008, according to the plaintiffs’ attorneys.

For many traders, CME memberships are “family legacies.” Some of them claim these seats were passed down through generations. The plaintiffs propounded that by moving the trading floor to Aurora and taking away membership benefits, CME devalued what they viewed as heirlooms.

The defendant insists that the rights and privileges associated with floor trading are still viable. Yet, per Chicago traders, screen-based platforms caused liquidity on the trading floors to tank, cutting the “life-support” of shouting brokers and hand signals in Chicago’s pits.

High stakes stifled by market impact 

Attorney Morrissey said the plaintiffs WOULD seek damages tied to the lost value of exclusive trading rights. 

“There’s the damage number for the value of the exclusivity right that members haven’t enjoyed for the past decade,” he reckoned. Additional damages would be limited to the individual memberships within the class.

Looking for more than financial restitution, the plaintiffs want a declaration from CME that Aurora qualifies as a trading floor. If the jury agrees, the operator may be forced to revise how it structures its membership benefits and trading access.

A ruling against CME could force corporate members that use single memberships to give access to multiple traders, at the expense of high costs under a revised membership structure. 

Moreover, the unresolved litigation could “roadblock” any potential merger talks involving CME. Sources close to the case say the dispute may deter Cboe Global Markets from entering negotiations, particularly if the stock is involved in the deal. 

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