Topstep Data Breach Exposes SSNs and Addresses

Topstep LLC, a Chicago-based proprietary trading firm, recently experienced a data breach that exposed personally identifiable information (PII) of individuals.

On Dec. 22, 2025, Topstep notified the Texas Attorney General of a cybersecurity event exposing the names, addresses, Social Security numbers, and other types of sensitive information.

The company reported the breach to the Indiana, Maine, and Massachusetts, and the New Hampshire attorneys general.

According to the Maine disclosure, a total of 1,920 individuals were affected by this breach. Citing their corresponding state attorney general office disclosures, there have been 222 individuals affected in Texas, 11 in Indiana, nine in Massachusetts, and one each in Maine and New Hampshire.

Topstep's response

In response to the breach, Topstep moved to contain the attack and engaged in a thorough investigation of its IT systems. The company notified affected consumers about the breach via U.S. Mail.

To support those affected, Topstep is offering complimentary access to Experian IdentityWorks for 24 months, which includes credit monitoring, identity restoration services and up to $1 million in identity theft insurance. Affected individuals are encouraged to remain vigilant by monitoring their credit reports, placing fraud alerts or security freezes with the major credit bureaus and reporting any suspicious activity to law enforcement.

The company’s notice provides detailed steps on how to enroll in the free credit monitoring service and how to contact Experian’s customer care team for assistance. Additional guidance is given for those who may experience tax-related identity theft, including instructions for contacting the IRS and filing the appropriate forms.

Impacted individuals can reach Topstep Customer Support at 888-407-1611 or by email at dpo@topstep.com.