---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-23-128325"
form_type: "8-K"
ticker: "NBBK"
cik: "0001979330"
company_name: "NB Bancorp, Inc."
filed_at: "2023-12-21T23:59:59+00:00"
generated_at: "2026-06-07T09:30:17.639129+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# NB Bancorp expects conversion and IPO close Dec 27; 40.9975M shares at $10 on Nasdaq

## Summary
- Conversion and IPO close expected Dec 27, 2023; shares to trade on Nasdaq under "NBBK" on Dec 28.
- Offering oversubscribed; 40,997,500 shares sold at $10.00 per share.
- ESOP intends to purchase up to 8% of outstanding shares (3,416,458) in open market.
- Company to contribute 1,708,229 shares and $2.0M cash to Needham Bank Charitable Foundation.
- Subscription oversubscribed by first-tier priority depositors; other orders not filled.

## SEC filing metadata
- accession: 0001104659-23-128325
- form_type: 8-K
- ticker: NBBK
- cik: 0001979330
- company_name: NB Bancorp, Inc.
- filed_at: 2023-12-21T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1979330/000110465923128325/0001104659-23-128325-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1979330/000110465923128325/tm2333547d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-23-128325
- JSON: https://secwatch.observer/filing/0001104659-23-128325.json
- Plain text: https://secwatch.observer/filing/0001104659-23-128325.txt

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