---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-26-090712"
form_type: "8-K"
ticker: "SBXD"
cik: "0002015947"
company_name: "SilverBox Corp IV"
filed_at: "2026-08-05T11:06:57+00:00"
generated_at: "2026-08-05T11:10:04.959558+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# SilverBox Corp IV extends business combination deadline to Dec 31, 2026

## Summary
- Second Amendment to BCA extends Outside Date from Aug 6, 2026 to Dec 31, 2026.
- Further extension allowed if SPAC obtains its own deadline extension, subject to mutual agreement.
- Amendment signed by all parties on Aug 4, 2026; original BCA dated Aug 6, 2025.
- Deal with Parataxis Holdings (digital assets/crypto) remains pending; SPAC avoids immediate liquidation.
- Prior First Amendment was dated May 1, 2026; this is the second amendment.

## SEC filing metadata
- accession: 0001104659-26-090712
- form_type: 8-K
- ticker: SBXD
- cik: 0002015947
- company_name: SilverBox Corp IV
- filed_at: 2026-08-05T11:06:57+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 1.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/2015947/000110465926090712/0001104659-26-090712-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/2015947/000110465926090712/tm2622195d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-26-090712
- JSON: https://secwatch.observer/filing/0001104659-26-090712.json
- Plain text: https://secwatch.observer/filing/0001104659-26-090712.txt

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