---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-237666"
form_type: "8-K"
ticker: null
cik: "0001825367"
company_name: "RayzeBio, Inc."
filed_at: "2023-09-19T23:59:59+00:00"
generated_at: "2026-06-10T13:46:02.266228+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# RayzeBio closes upsized IPO of 19.87M shares at $18.00, raising ~$336.7M gross proceeds

## Summary
- Closed IPO of 19,869,240 shares at $18.00 per share, including full exercise of underwriters' option for 2,591,640 additional shares.
- Gross proceeds to RayzeBio of approximately $336.7 million before underwriting discounts and expenses.
- Selling stockholder sold 1,163,000 shares; RayzeBio received no proceeds from those sales.
- Shares began trading on Nasdaq Global Market on September 15, 2023 under ticker RYZB.
- Joint book-running managers: J.P. Morgan, Jefferies, Evercore ISI, Truist Securities.

## SEC filing metadata
- accession: 0001193125-23-237666
- form_type: 8-K
- cik: 0001825367
- company_name: RayzeBio, Inc.
- filed_at: 2023-09-19T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 5.03, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1825367/000119312523237666/0001193125-23-237666-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1825367/000119312523237666/d474188d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-237666
- JSON: https://secwatch.observer/filing/0001193125-23-237666.json
- Plain text: https://secwatch.observer/filing/0001193125-23-237666.txt

## Key facts
- Governance Changes
  RayzeBio, Inc.: Amended and restated certificate of incorporation filed in connection with closing of IPO (effective 2023-09-19).
  - Change: charter amendment
  - Effective: 2023-09-19
  source text: the Company filed an amended and restated certificate of incorporation (the “Restated Certificate”) with the Secretary of State of the State of Delaware.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1825367/000119312523237666/0001193125-23-237666-index.htm
- Governance Changes
  RayzeBio, Inc.: Amended and restated bylaws adopted in connection with closing of IPO (effective 2023-09-19).
  - Change: bylaw amendment
  - Effective: 2023-09-19
  source text: the Company adopted amended and restated bylaws (the “Restated Bylaws”) in connection with the closing of the IPO.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1825367/000119312523237666/0001193125-23-237666-index.htm

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