HFT Solutions Technologies, LLC v. Citadel Securities, LLC

HFT Solutions Technologies, LLC initiated this patent infringement lawsuit against Citadel Securities, LLC in the United States District Court for the Northern District of Illinois, alleging infringement of three patents related to high-frequency trading technology. Plaintiff HFT Solutions Technologies, LLC is a wholly-owned subsidiary of Network-1 Technologies, Inc., a publicly traded company engaged in the acquisition, development, licensing, and monetization of intellectual property, positioning HFT Solutions as a patent assertion entity (PAE). While HFT Technologies also describes itself as a provider of ultra-low latency trading infrastructure and algorithmic trading solutions, its parent company's stated business model primarily focuses on IP monetization. The defendant, Citadel Securities, LLC, is a leading American market-making firm, headquartered in Miami, Florida (formerly Chicago), providing liquidity and trade execution services to retail and institutional clients globally. Citadel Securities utilizes advanced technology, including quantitative research, machine learning, and AI, in its operations as a major player in high-frequency trading.

The core of the dispute centers on Citadel Securities' alleged infringement of U.S. Patent No. 10,931,286, U.S. Patent No. 11,128,305, and U.S. Patent No. 11,575,381. All three patents are titled "Field programmable gate array with external phase-locked loop" and generally relate to Field-Programmable Gate Array (FPGA) systems. Specifically, these patents describe technologies for processing data streams using FPGA systems that provide phase control with minimal latency, aiming to achieve critical transaction latency gains in high-frequency trading systems where speed is paramount. HFT Solutions alleges that Citadel Securities' "systems and platforms," including those incorporating FPGA boards, infringe these patents.

The case, assigned case number 1:24-cv-13213, was filed on December 26, 2024, in the Northern District of Illinois and is currently active. District Judge Sharon Johnson Coleman is the presiding judge, with Magistrate Judge Beth W. Jantz handling certain procedural matters like status hearings. The procedural posture has seen significant activity, with Citadel Securities filing a motion to dismiss on April 7, 2025, arguing that the asserted patents were directed to patent-ineligible subject matter under 35 U.S.C. § 101; this motion was denied by the Court on December 1, 2025. Citadel subsequently filed its answer and counterclaims for non-infringement and invalidity on January 5, 2026. This litigation is notable due to HFT Solutions' pattern of patent assertion against key players in the high-frequency trading market, as evidenced by a parallel suit filed against Jump Trading, LLC on the same day with the same patents. The denial of the § 101 motion underscores the ongoing challenges and importance of patent eligibility in software-related and financial technology inventions.

HFT Solutions Technologies, LLC v. Citadel Securities, LLC (1:24-cv-13213, N.D. Ill.) is an active patent infringement lawsuit. The plaintiff, HFT Solutions Technologies, LLC, a subsidiary of Network-1 Technologies, Inc., accuses Citadel Securities, LLC of infringing three patents: US Patent 10931286, US Patent 11575381, and US Patent 11575305.

Here's a chronological breakdown of the key legal developments:

• Complaint Filed (2024-12-26): HFT Solutions Technologies, LLC initiated the lawsuit against Citadel Securities, LLC, alleging infringement of US Patents 10931286, 11575381, and 11575305.
• Motion to Dismiss Filed by Citadel (before 2025-12-01): Citadel Securities, LLC filed a motion to dismiss HFT's complaint under Federal Rule of Civil Procedure 12(b)(6), arguing that the asserted patent claims were patent-ineligible under 35 U.S.C. § 101.
• Motion to Dismiss Denied (2025-12-01): The Court, presided over by the Honorable Sharon Johnson Coleman, denied Citadel's motion to dismiss. The court's memorandum opinion and order addressed the patent eligibility of claims related to processing data streams using field-programmable gate array (FPGA) systems, noting that the patents address a technological issue causing "unwanted latency" in FPGAs.
• Answer and Counterclaims Filed (2026-01-05): Citadel Securities, LLC filed its Answer to the Complaint, which also included a jury demand and counterclaims against HFT Solutions, LLC.
• Status Hearing (2026-05-29): A status hearing in the case was scheduled for May 29, 2026, at 2:00 PM, before Magistrate Judge Beth W. Jantz. As of the current date, this hearing would have occurred or is presently underway.

Parallel PTAB IPR/PGR Proceedings:
No information regarding parallel PTAB IPR or PGR proceedings specifically initiated by Citadel Securities, LLC against US Patent 10931286, 11575381, or 11575305 was found in the conducted searches. While IPRs and PGRs are common in patent litigation as a faster and cheaper alternative to district court challenges, there is no public record indicating such filings in this specific case.

Current Posture:
The case is currently active and ongoing in the United States District Court for the Northern District of Illinois. The denial of the motion to dismiss indicates the case will proceed to further stages of litigation, such as claim construction and discovery, unless a settlement is reached. There have been no reported outcomes regarding claim construction (Markman), discovery milestones, trial events, verdict, post-trial motions, settlement, or final judgment to date beyond the motion to dismiss.

Plaintiff HFT Solutions Technologies, LLC is represented by attorneys from Russ August & Kabat, with their primary office in Los Angeles, California. Given the requirement for local counsel in the Northern District of Illinois for non-resident attorneys, it is highly probable that additional local counsel has been engaged.

The following attorneys from Russ August & Kabat have been identified as representing HFT Solutions, LLC in this case, or a closely related parallel case involving similar patents and the same plaintiff in the Northern District of Illinois:

• Marc A. Fenster (Lead Counsel)

  • Firm: Russ August & Kabat, Los Angeles, California.
  • Experience: Mr. Fenster is co-chair of the Litigation Department and chair of the Patent Litigation department at Russ August & Kabat, specializing in high-technology patent litigation as a first-chair trial lawyer. He has secured numerous multi-million dollar jury verdicts for his clients in patent infringement cases, including against Samsung and Western Digital, and is consistently recognized among top patent and intellectual property lawyers.

• Paul A. Kroeger (Counsel)

  • Firm: Russ August & Kabat, Los Angeles, California.
  • Experience: Mr. Kroeger is a litigation partner at Russ August & Kabat and a member of the firm's plaintiff's patent infringement litigation group, focusing on complex business and intellectual property litigation. He has successfully represented clients in federal district courts in intellectual property matters.

• Dale Chang (Counsel)

  • Firm: Russ August & Kabat, Los Angeles, California.
  • Experience: Mr. Chang represents clients in high-stakes patent and trade secrets litigation, with significant trial experience in various patent venues including district courts, the International Trade Commission (ITC), and the Patent Trial and Appeal Board (PTAB). He has played instrumental roles in securing substantial jury verdicts in patent suits.

• Brian D. Ledahl (Counsel)

  • Firm: Russ August & Kabat, Los Angeles, California.
  • Experience: Mr. Ledahl is listed among the patent litigation attorneys at Russ August & Kabat and has been involved in significant patent trial wins.

• Joshua Scheufler (Counsel)

  • Firm: Russ August & Kabat, Los Angeles, California.
  • Experience: Mr. Scheufler is listed as counsel for HFT Solutions, LLC in this matter.

As of the current date, specific local counsel for HFT Solutions Technologies, LLC in the Northern District of Illinois has not been explicitly identified in the provided search results. Local Rule 83.15(a) of the Northern District of Illinois requires an attorney not having an office within the district to designate local counsel who is a member of the bar of that Court and has an office within the district. [cite: 14 (from prior search)]

The defendant, Citadel Securities, LLC, is represented by attorneys from two prominent law firms: Kirkland & Ellis LLP and Bartlit Beck LLP, both with offices in Chicago, Illinois.

Here is the counsel of record for Citadel Securities:

Kirkland & Ellis LLP (Chicago, IL)

• Amanda Hollis, P.C. - Partner (Lead Counsel)
  • Ms. Hollis is an intellectual property litigator with extensive experience in patent cases in federal courts and the ITC, including inter partes reviews before the PTAB. She has a track record of obtaining successful results for clients in high-stakes patent litigation across various technologies.
• Adam M. Janes - Partner (Lead Counsel)
  • Mr. Janes practices intellectual property litigation, focusing on patent infringement, trade secret misappropriation, and unfair competition matters in federal courts, the USPTO, and the ITC. He also advises clients on IP acquisition, risk, and monetization.
• Brian A. Verbus - Partner
  • Mr. Verbus is an intellectual property litigation partner with experience across a range of technologies, including electronics, pharmaceuticals, and medical devices. He has experience in all phases of patent litigation, from claim construction to appeals to the Federal Circuit.
• Jay J. Emerick, P.C. - Partner
  • Mr. Emerick focuses his practice on patent infringement cases in district court, the ITC, the PTAB, and on appeal at the Federal Circuit, representing clients in a broad range of technologies.

Bartlit Beck LLP (Chicago, IL)

• Matthew R. Ford - Partner (Lead Counsel)
  • Mr. Ford is a trial lawyer specializing in patent litigation and complex commercial disputes. He has been part of trial teams that secured significant jury verdicts in patent infringement cases and has represented major companies in technology law matters.
• Rebecca T. Horwitz - Partner (Lead Counsel)
  • Ms. Horwitz is a nationally recognized patent and trial litigator, known for her innovative approach to complex patent litigation and for achieving successful outcomes for clients. She has secured inter partes review and appellate victories and won jury trials in patent infringement cases.

Citadel Securities also has a robust in-house legal team. Ryan VanGrack is the Managing Director and General Counsel at Citadel Securities, overseeing all legal affairs in the U.S. and North/South America, including litigation. Brooke Cucinella, Global Head of Litigation & Regulatory Inquiries for Citadel and Citadel Securities, oversees all litigation and enforcement-related matters for both entities. Other in-house counsel include Guy Miller, Senior Deputy General Counsel, who is responsible for legal and regulatory aspects of Citadel Securities' business.