Quintara Biosciences v. Ruifeng

The Ninth Circuit held the federal Defend Trade Secrets Act does not force plaintiffs to identify secrets with reasonable particularity before discovery, splitting from California's state-law rule.

How specifically must a plaintiff describe its trade secrets, and how early? That recurring procedural fight got an important answer in Quintara Biosciences, Inc. v. Ruifeng Biztech, Inc., No. 23-16093, 2025 WL 2315671 (9th Cir. Aug. 12, 2025). Writing for the panel, Judge Anthony Johnstone held that the federal Defend Trade Secrets Act does not require a plaintiff to identify its secrets with “reasonable particularity” before discovery begins — and that a district court abused its discretion when it struck most of a plaintiff’s claimed secrets at the starting line. The ruling pulls federal practice apart from California’s distinctive state-law disclosure rule and reshapes the early choreography of DTSA litigation in the nation’s largest circuit.

At a glance

Case: Quintara Biosciences, Inc. v. Ruifeng Biztech, Inc., No. 23-16093 (9th Cir. Aug. 12, 2025).
Court: United States Court of Appeals for the Ninth Circuit; opinion by Judge Anthony D. Johnstone, joined by Judge Lawrence VanDyke and District Judge Dana L. Christensen (sitting by designation).
Posture: Appeal from the Northern District of California, which had struck nine of the plaintiff’s claimed trade secrets before discovery and entered judgment narrowing the case.
Holding: The DTSA does not require identifying trade secrets with reasonable particularity at the outset of discovery; particularity is a fact question for later stages. Striking the secrets pre-discovery was an abuse of discretion.
Significance: Decouples federal DTSA pleading and disclosure from California Code of Civil Procedure § 2019.210, easing plaintiffs’ early burden in the Ninth Circuit.

A partnership that fell apart

Quintara Biosciences and Ruifeng Biztech are both DNA-sequencing-analysis companies. They had a working relationship from 2013 to 2019, and when it collapsed, Quintara alleged that Ruifeng locked it out of its office, seized its equipment, and hired away its employees. Quintara sued under the DTSA, asserting that Ruifeng had misappropriated its trade secrets — among them customer and vendor databases, marketing plans, and proprietary technology. In its operative pleading Quintara identified a set of distinct claimed secrets.

The litigation snagged not on the merits but on identification. The district court, borrowing from California state practice, ordered Quintara to disclose its trade secrets with “reasonable particularity” at the outset of discovery. When the court found the descriptions wanting, it struck nine of the claimed secrets, leaving only two to proceed. That ruling effectively gutted the case before discovery could flesh out the contours of what had been taken — and it teed up the appeal.

The Section 2019.210 question

California Code of Civil Procedure § 2019.210 requires a plaintiff bringing a state trade-secret claim to identify the trade secret with reasonable particularity before commencing discovery relating to it. That rule is a deliberate feature of California practice, meant to prevent plaintiffs from using discovery to fish for secrets they cannot yet describe. The question in Quintara was whether that state procedural gate applies to a federal DTSA claim litigated in federal court.

The Ninth Circuit said no. The DTSA contains no analogue to § 2019.210, and the panel declined to graft the state requirement onto the federal statute. Federal courts manage discovery under the Federal Rules, the court reasoned, and the DTSA’s text does not condition discovery on an early particularized disclosure. The state rule, however sensible in its own forum, is not part of the federal cause of action.

Particularity as a fact question, not a gate

The panel reframed identification as a merits question rather than a threshold filter. Whether a trade secret has been identified with sufficient particularity, the court held, is a question of fact to be resolved at summary judgment or trial — the points at which the record is developed enough to test the claim. The court endorsed an “iterative process” in which requests between the parties refine and sharpen the trade-secret identification over the course of discovery.

That does not mean anything goes. The court reaffirmed that a plaintiff “may not simply rely upon catchall phrases or identify categories of trade secrets,” and ultimately must show that the claimed secret has “sufficient particularity to separate it from matters of general knowledge in the trade or of special knowledge of those persons skilled in the trade.” The difference is timing: the plaintiff must meet that standard to prevail, but need not satisfy it as a precondition to taking discovery. District courts retain broad discretion to manage trade-secret discovery — but striking claims wholesale before discovery, the panel held, exceeded that discretion here.

Open questions

How will district courts manage discovery now? The opinion preserves judicial discretion to sequence and structure trade-secret discovery; how aggressively courts use it after Quintara remains to be seen.
What counts as a “catchall”? The line between an impermissibly vague category and an adequately bounded secret is still fact-intensive and will be litigated case by case.
Will other circuits follow? The decision deepens the contrast between federal DTSA practice and state particularity regimes, raising the prospect of divergent approaches across circuits.

Implications

DTSA plaintiffs get breathing room. In the Ninth Circuit, plaintiffs need not pin down every secret with reasonable particularity before discovery, lowering the early dismissal risk.
State rules do not automatically travel. Section 2019.210 governs California state claims but does not bind a federal DTSA claim, even in a California federal court.
Identification is a merits battle. Particularity disputes now play out at summary judgment and trial, so defendants should preserve the issue rather than expect an early knockout.
Catchalls still lose. The substantive standard is unchanged; vague category descriptions will fail when the record is tested, just not at the threshold.
Discovery management still matters. Courts keep wide discretion to structure trade-secret discovery, so plaintiffs should expect iterative refinement demands even without an upfront gate.

Frequently asked questions

What did the Ninth Circuit hold in Quintara v. Ruifeng? It held that the federal Defend Trade Secrets Act does not require a plaintiff to identify its trade secrets with reasonable particularity before discovery begins. Whether a secret is identified with sufficient particularity is a question of fact for summary judgment or trial, not a gatekeeping requirement at the outset.

How does this differ from California state law? California’s Code of Civil Procedure Section 2019.210 requires a trade-secret plaintiff suing under state law to identify its secrets with reasonable particularity before commencing discovery. The Ninth Circuit held that this state rule does not import into a federal DTSA claim.

What happened to Quintara’s claims? The district court had struck nine of Quintara’s claimed trade secrets at the discovery stage for lack of particularity. The Ninth Circuit reversed and remanded, holding the district court abused its discretion by striking the secrets before discovery developed them.