Mid-2025 Patent Daubert Roundup: Six Months of Rulings

H1 2025 Daubert merits rulings in patent cases tracked the pattern that has defined the post-amendment period. Partial exclusions outnumbered full exclusions by roughly 2 to 1. The split across the three reliability prongs (qualifications, methodology, fit) was consistent with 2024. The forums concentrated, the same way they have for the last three years, in three districts.

The headline finding is continuity, not disruption. The 2023 amendment to Rule 702 continues to do its work at the partial-exclusion margin. Damages experts continue to draw more challenges than technical experts. The Federal Circuit reinforced both trends in EcoFactor, decided en banc in May 2025.

Volume and court concentration

Patent Daubert motion practice in H1 2025 was concentrated in three districts: the Eastern District of Texas, the Western District of Texas, and the District of Delaware. Together these three forums accounted for the majority of merits rulings on patent expert testimony in the period.

The concentration tracks the underlying patent docket, not anything specific to Daubert. E.D. Texas remains the highest-volume patent venue. W.D. Texas (Waco) continues to draw a substantial share of patent filings despite the post-2022 transfer-out pattern. D. Del. continues to draw transferred and consolidated patent litigation. The Daubert practice follows the cases.

The aggregate outcome split in H1 2025 held to the post-amendment baseline. Roughly half of merits rulings admitted the expert testimony in full. Roughly a third resulted in partial exclusion, meaning some opinions were struck while others survived. The remaining rulings were full exclusions. The 2-to-1 partial-to-full ratio that emerged after the December 2023 amendment did not shift in H1 2025.

Technical experts vs damages experts

The aggregate numbers obscure a sharper split by expert type. Technical experts on infringement, validity, and POSITA framing draw fewer Daubert motions and survive more of them. Damages experts draw more motions and survive fewer of them.

The reason is structural. Technical expert testimony at the gatekeeping stage usually turns on qualifications and the application of an accepted analytical framework to the claim limitations. The methodology is well-established, and Daubert challenges typically target fit (whether the expert's analysis matches the claim construction) rather than reliability.

Damages expert testimony is different. The reasonable-royalty analysis under Georgia-Pacific has more discretionary points than infringement analysis, and each discretionary point is a Rule 702 entry point. Apportionment, comparable-license selection, the date of the hypothetical negotiation, the royalty base, the running rate, the lump-sum conversion: each can be challenged as unreliable or unfit.

In H1 2025, damages experts faced full or partial exclusion at rates measurably higher than technical experts. The gap mirrors the post-EcoFactor reckoning on royalty-rate methodology and the courts' growing comfort with striking damages opinions that do not show the work.

Post-EcoFactor activity

EcoFactor v. Google (Fed. Cir. 2025) (en banc), decided in May 2025, vacated a damages award based on a royalty-rate analysis that the en banc court found insufficiently tied to the cited comparable licenses. The decision did not announce a new rule. It applied the existing Rule 702 reliability standard to a familiar fact pattern, and it framed the problem as a gatekeeping failure.

The downstream effect in H1 2025 was visible. Damages-expert Daubert motions citing EcoFactor appeared in district-court filings within weeks of the decision. Motion practice on comparable-license selection picked up. Courts began applying the EcoFactor reasoning to apportionment challenges, even where the underlying methodology was different.

The motion-to-exclude lifecycle is short. A May 2025 Federal Circuit decision shows up in district court motion practice in June, in briefing in July, and in trial-court rulings by August. The August 2025 rulings in this corpus include several that cite EcoFactor expressly and follow its reasoning to partial exclusion of damages testimony.

What changed and what did not

What changed: damages experts are now operating under a Federal Circuit reaffirmation of the comparable-licenses rigor. Royalty-rate testimony that recites a number without working through the comparable-license analysis is at higher risk than it was 12 months ago.

What did not change: the aggregate outcome split, the court concentration, the technical-expert survival rate, the partial-to-full ratio. The 2023 amendment continues to do its work at the partial-exclusion margin, and the Federal Circuit continues to back that work without disrupting the underlying framework.

For retaining counsel, the practical takeaway is the same one that has held since December 2023. Build the methodology before the deadline. Tie every conclusion to a citable source. Anticipate the partial-exclusion motion, because partial exclusion is now the modal outcome, not full admission.

A note on the data

The H1 2025 figures above draw on Daubert merits rulings on patent expert testimony on WitnessLens. Merits rulings are defined as district court orders that reach the reliability or fit prongs of Rule 702, excluding orders denied as untimely or as duplicative of earlier rulings in the same case. The outcome split (admitted, partial exclusion, full exclusion) is calculated per expert per ruling. Methodology details are on the methodology page.