Ninth Circuit Clarifies DTSA’s “Sufficient Particularity” for Identifying Trade Secrets

Trade secret litigation under the Defend Trade Secrets Act (DTSA) continues to evolve within the Ninth Circuit.

Two landmark recent decisions—Quintara Biosciences v. Ruifeng Biztech (Aug. 12, 2025) and Zunum Aero v. The Boeing Co. (Aug. 14, 2025)—offer critical guidance on how early trade secret claims must be pled and when judgments on appeal are appropriate. Although each case presents its unique factual context, together they reflect the court’s continued effort to shape the jurisprudential boundaries of “sufficient particularity” under the DTSA:

• For plaintiffs, the DTSA and the California Uniform Trade Secrets Act (CUTSA) have distinct requirements on specificity of trade secrets at the initial states of the case—DTSA is fact intensive, and determinations should wait for summary judgment or trial;
• Plaintiffs should also be specific and clear by the end of fact discovery to build a strong record for trial and subsequent appeal;
• Defendants can (and should) knock out CUTSA claims early, especially if they are just a basis for jurisdiction; and
• Defendants should contest economic value early and often is critical to success.

Quintara Biosciences v. Ruifeng Biztech (No. 23-16093)

Facts: Quintara and Ruifeng, two California-based DNA sequencing and analysis companies, ended their business relationship amid allegations that Ruifeng locked Quintara out of its offices, seized equipment and hired its employees. Quintara sued under the DTSA, alleging misappropriation of nine trade secrets, including customer and vendor databases, marketing plans, software code and proprietary DNA reagent protocols.

Procedural History and Issue:  During discovery, the district court—relying on CUTSA’s pre-disclosure requirement under Cal. Civ. Proc. Code Section 2019.210—ordered Quintara to identify trade secrets with “reasonable particularity” before advancing discovery. When Quintara produced an amended disclosure, Ruifeng moved to strike those secrets that didn’t meet the standard under Rule 12(f). The district court struck nine of 11 claimed secrets.

The Ninth Circuit reversed, ruling that:

1. CUTSA’s “reasonable particularity” rule does not apply to DTSA cases, which impose no timing or pre-discovery requirement for identifying trade secrets;
2. Under DTSA, whether a claim meets “sufficient particularity” is a fact-intensive question to be resolved at summary judgment or trial—not in pre-discovery motions to strike;
3. Rule 12(f) does not authorize striking trade secrets for lack of early specificity; and
4. Striking the claims as a discovery sanction under Rule 37 or Rule 16 was an abuse of discretion in the absence of extreme circumstances.

Zunum Aero v. The Boeing Co. (No. 24-5212)

Facts: Zunum Aero, a startup developing electric commuter aircraft, received a $5 million investment from Boeing in 2017. Zunum alleged Boeing misappropriated its trade secrets to advance its own hybrid aircraft. A jury found Boeing liable and awarded approximately $72 million in damages (later adjusted to ~$81 million including disgorgement and interest).

Procedural History and Issue: Despite the jury verdict, the presiding district judge vacated the award, concluding that Zunum failed to identify its trade secrets with sufficient particularity or show that their value derived from secrecy.

The Ninth Circuit reversed, reinstating the jury verdict, and in rejecting Boeing’s motion for judgement as a matter of law, it held that:

1. Zunum adequately identified its trade secrets with sufficient specificity, allowing the jury to evaluate their protectability;
2. Substantial evidence supported that Zunum’s secrets derived independent economic value from not being generally known, and that Boeing misappropriated them; and
3. The district court’s dismissal improperly re-weighed evidence instead of drawing all reasonable inferences in Zunum’s favor.

Lessons and Litigation Strategy

Taken together, the Ninth Circuit’s twin decisions in Quintara and Zunum Aero signal a robust, fact-oriented approach to trade secret litigation under the DTSA. Although plaintiffs appear to have more initial leeway in defining secrets, they must follow through with credible, detailed assertions later in litigation. Defendants must prepare to contest misappropriation, specificity and economic value through discovery and trial—not premature motions.

This document is intended to provide you with general information regarding trade secret litigation and case law in the Ninth Circuit. The contents of this document are not intended to provide specific legal advice. If you have any questions about the contents of this document or if you need legal advice as to an issue, please contact the attorneys listed or your regular Brownstein Hyatt Farber Schreck, LLP attorney. This communication may be considered advertising in some jurisdictions. The information in this article is accurate as of the publication date. Because the law in this area is changing rapidly, and insights are not automatically updated, continued accuracy cannot be guaranteed.