Unreported / Non-Citable
Background
Plaintiff Akemi Tanaka filed suit against Caris MPI, Inc. (doing business as Caris Life Sciences) and Does 1 through 50 in the United States District Court for the Southern District of California. The case was assigned Case No. 25-cv-1376-BJC-MSB. On September 28, 2026, the court denied Caris MPI, Inc.'s Motion to Compel Arbitration (ECF No. 28). Following that denial, Caris MPI, Inc. filed a notice of appeal to the United States Court of Appeals for the Ninth Circuit on October 9, 2026 (ECF No. 29), challenging the order denying the motion to compel arbitration.
The appeal triggered the automatic stay framework established by the Supreme Court in Coinbase, Inc. v. Bielski, 599 U.S. 736 (2023). In Coinbase, the Court held that when a federal district court denies a motion to compel arbitration and the losing party appeals that decision, the district court must stay its pre-trial and trial proceedings while the interlocutory appeal is ongoing. The present case presented a direct application of that rule, requiring the district court to halt all proceedings pending the Ninth Circuit's resolution of the appeal.
The order was signed by District Judge Benjamin J. Cheeks on October 21, 2026. The court's ruling was procedural in nature, implementing the mandatory stay required by Supreme Court precedent rather than addressing the merits of the underlying arbitration dispute or the plaintiff's substantive claims.
The Court’s Holding
The court ordered a stay of the entire action and vacated all currently scheduled hearings and deadlines pending resolution of the interlocutory appeal before the Ninth Circuit. Specifically, the Clerk of Court was directed to vacate the December 3, 2026 Pretrial Conference and to stay the matter. The court relied on Coinbase, Inc. v. Bielski, 599 U.S. 736, 738 (2023), which mandates that district courts must halt pre-trial and trial proceedings once a notice of appeal is filed from an order denying a motion to compel arbitration.
The stay is mandatory and self-executing upon the filing of the notice of appeal; no discretionary balancing of factors is required. The court did not rule on the merits of the underlying arbitration dispute or the appeal itself, but solely implemented the procedural requirement imposed by the Supreme Court. All proceedings in the district court are suspended until the Ninth Circuit resolves the appeal of the order denying the motion to compel arbitration.
The order also directed the Clerk of Court to vacate the December 3, 2026 Pretrial Conference specifically, ensuring that no scheduled proceedings would occur during the pendency of the appeal. This directive reflects the comprehensive nature of the stay, which extends to all pre-trial activities and deadlines.
Key Takeaways
- A district court must stay all pre-trial and trial proceedings when a party appeals an order denying a motion to compel arbitration.
- The stay obligation arises automatically upon the filing of a notice of appeal and is not subject to the court's discretion.
- The Supreme Court's decision in Coinbase, Inc. v. Bielski, 599 U.S. 736 (2023), controls this procedural requirement in federal courts.
- Scheduled hearings and deadlines, including pretrial conferences, must be vacated during the pendency of the interlocutory appeal.
- The underlying merits of the arbitration motion and the plaintiff's claims remain unresolved and are unaffected by the stay.
Why It Matters
This order illustrates the immediate and mandatory effect of the Coinbase rule on district court management. Once a notice of appeal is filed from a denial of a motion to compel arbitration, the district court must halt pre-trial and trial activities until the appellate court resolves the appeal. The decision reinforces the strong federal policy favoring arbitration and ensures that the right to arbitrate is not effectively mooted by continued litigation in the district court during the appeal.
Practitioners must be aware that filing such an appeal automatically halts the case, which can significantly delay resolution of the underlying dispute. The order also demonstrates the practical application of the Coinbase rule in a district court setting, where the court promptly stayed all proceedings and vacated scheduled hearings upon learning of the interlocutory appeal. This case serves as a reminder that the stay is mandatory and not subject to the district court's discretion.