---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-201397"
form_type: "8-K"
ticker: "ATRA"
cik: "0001604464"
company_name: "Atara Biotherapeutics, Inc."
filed_at: "2026-05-01T23:59:59+00:00"
generated_at: "2026-05-15T00:19:10.571924+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Atara Biotherapeutics receives Nasdaq delisting notice for market value deficiency

## Summary
- Nasdaq notified Atara on April 30, 2026, that its MVLS fell below $50M for 30 consecutive business days.
- Company has 180 calendar days, until October 27, 2026, to regain compliance by closing at $50M+ for 10+ consecutive days.
- Stock continues trading on Nasdaq Global Select under ticker ATRA; company may consider transfer to Nasdaq Capital Market.
- If not compliant by deadline, Nasdaq will provide delisting notice; Atara may appeal to a Hearings Panel.

## SEC filing metadata
- accession: 0001193125-26-201397
- form_type: 8-K
- ticker: ATRA
- cik: 0001604464
- company_name: Atara Biotherapeutics, Inc.
- filed_at: 2026-05-01T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 3.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1604464/000119312526201397/0001193125-26-201397-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1604464/000119312526201397/atra-20260430.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-201397
- JSON: https://secwatch.observer/filing/0001193125-26-201397.json
- Plain text: https://secwatch.observer/filing/0001193125-26-201397.txt

## Source-grounded claims
- claim_id: 3002767de5fbe4a3f6687b683be8d1044530b77d
  claim: Atara Biotherapeutics, Inc. received a nasdaq deficiency notice notice regarding market value (rules 5450(b)(2)(A), 5810(c)(3)(C)).
  evidence_excerpt: April 30, 2026, Atara Biotherapeutics, Inc. (the “Company”) received a notice (the “Notice”) from the Listing Qualifications Department (the “Staff”) of The Nasdaq Stock Market LLC (“Nasdaq”) notifying the Company that t
  evidence_url: https://www.sec.gov/Archives/edgar/data/1604464/000119312526201397/0001193125-26-201397-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.