---
schema_version: "secwatch.filing_event.v1"
accession: "0001558370-25-009290"
form_type: "8-K"
ticker: null
cik: "0001733294"
company_name: "Generation Bio Co."
filed_at: "2025-07-18T23:59:59+00:00"
generated_at: "2026-05-18T05:47:08.215957+00:00"
event_type: "other"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# Generation Bio to implement 1-for-10 reverse stock split to regain Nasdaq compliance

## Summary
- Effective 5:00 pm ET July 21, 2025; every 10 shares combine into 1.
- Outstanding shares reduce from ~67.3M to ~6.7M.
- No fractional shares issued; cash payments for fractional shares.
- Split-adjusted trading begins July 22 under ticker GBIO, new CUSIP 37148K 209.
- Purpose: meet Nasdaq minimum bid price requirement for continued listing.

## SEC filing metadata
- accession: 0001558370-25-009290
- form_type: 8-K
- cik: 0001733294
- company_name: Generation Bio Co.
- filed_at: 2025-07-18T23:59:59+00:00
- event_type: other
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 3.03, 5.03, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1733294/000155837025009290/0001558370-25-009290-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1733294/000155837025009290/gbio-20250718x8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001558370-25-009290
- JSON: https://secwatch.observer/filing/0001558370-25-009290.json
- Plain text: https://secwatch.observer/filing/0001558370-25-009290.txt

## Key facts
- Governance Changes
  Generation Bio Co.: Filed Certificate of Amendment to effect a 1-for-10 reverse stock split of common stock, effective July 21, 2025 (effective 2025-07-21).
  - Change: charter amendment
  - Effective: 2025-07-21
  source text: On July 18, 2025, Generation Bio Co. (the “Company”) filed a Certificate of Amendment to the Company’s Amended and Restated Certificate of Incorporation (the “Certificate of Amendment”) with the Secretary of State of the State of Delaware, which will effect, as of 5:00 p.m. Eastern Time, on July 21, 2025 (the “Effective Time”), a 1-for-10 reverse stock split
  evidence_url: https://www.sec.gov/Archives/edgar/data/1733294/000155837025009290/0001558370-25-009290-index.htm

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