---
schema_version: "secwatch.filing_event.v1"
accession: "0001628280-25-043137"
form_type: "8-K"
ticker: "OSG"
cik: "0000874501"
company_name: "OCTAVE SPECIALTY GROUP INC"
filed_at: "2025-09-29T23:59:59+00:00"
generated_at: "2026-05-17T05:30:11.468654+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Ambac to acquire ArmadaCare from SiriusPoint for $250M, expects Q4 2025 close

## Summary
- Purchase price $250M; financed with $100M term loan and $20M revolver from Truist.
- Transaction expected to close Q4 2025, subject to customary regulatory approvals.
- Deal expected to be accretive to Ambac shareholders in 2026.
- ArmadaCare CEO Ed Walker to continue leading the business; new 5-year capacity agreement with SiriusPoint.
- Investor call on Sept 30 at 8:30am ET to discuss strategic update.

## SEC filing metadata
- accession: 0001628280-25-043137
- form_type: 8-K
- ticker: OSG
- cik: 0000874501
- company_name: OCTAVE SPECIALTY GROUP INC
- filed_at: 2025-09-29T23:59:59+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 1.01, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/874501/000162828025043137/0001628280-25-043137-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/874501/000162828025043137/ambc-20250929.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001628280-25-043137
- JSON: https://secwatch.observer/filing/0001628280-25-043137.json
- Plain text: https://secwatch.observer/filing/0001628280-25-043137.txt

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