---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-374787"
form_type: "8-K"
ticker: "BOLD"
cik: "0001782303"
company_name: "Boundless Bio, Inc."
filed_at: "2026-08-28T21:25:54+00:00"
generated_at: "2026-08-28T21:28:14.929721+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# Boundless Bio amends Serapha merger: RSU conversion, pre-funded warrants, vote standard

## Summary
- Amendment No. 1 (8/28/26) to the June 22, 2026 merger agreement among Boundless Bio, Boulder Merger Sub, and Serapha Bio.
- Serapha RSUs (vested or unvested) convert into Assumed RSUs covering Boundless Bio common stock at the Exchange Ratio.
- Pre-funded warrants with $0.00001 exercise price issued as Merger Consideration for holders exceeding Beneficial Ownership Limits (0–19.99%).
- Vote standard for increasing authorized Boundless Bio shares changed to majority of shares properly cast, not majority outstanding.
- Company Pre-Closing Financing definitions clarified; cash proceeds of at least the minimum amount required by 8/28/26 close.

## SEC filing metadata
- accession: 0001193125-26-374787
- form_type: 8-K
- ticker: BOLD
- cik: 0001782303
- company_name: Boundless Bio, Inc.
- filed_at: 2026-08-28T21:25:54+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 1.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1782303/000119312526374787/0001193125-26-374787-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1782303/000119312526374787/d111273d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-374787
- JSON: https://secwatch.observer/filing/0001193125-26-374787.json
- Plain text: https://secwatch.observer/filing/0001193125-26-374787.txt

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