---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-21-251963"
form_type: "8-K"
ticker: "WMS"
cik: "0001604028"
company_name: "ADVANCED DRAINAGE SYSTEMS, INC."
filed_at: "2021-08-20T23:59:59+00:00"
generated_at: "2026-06-29T08:39:31.814927+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Advanced Drainage Systems enters shareholder agreement with CPPIB after 3.1M share purchase from Chlapaty trust

## Summary
- CPPIB purchased 3.1M shares from Joseph Chlapaty trust; company received no proceeds.
- Shareholder Agreement imposes transfer restrictions and standstill obligations on CPPIB's Active Equities Group until later of 2 years or below 5% ownership.
- Registration Rights Agreement grants CPPIB demand and piggyback registration rights, subject to $50M minimum and certain limits.
- Company waived consent right to CPPIB's acquisition of remaining shares via ROFO.
- Standstill limits CPPIB from owning >9.99% without Board consent, up to 20% with consent.

## SEC filing metadata
- accession: 0001193125-21-251963
- form_type: 8-K
- ticker: WMS
- cik: 0001604028
- company_name: ADVANCED DRAINAGE SYSTEMS, INC.
- filed_at: 2021-08-20T23:59:59+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/1604028/000119312521251963/0001193125-21-251963-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1604028/000119312521251963/d192515d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-21-251963
- JSON: https://secwatch.observer/filing/0001193125-21-251963.json
- Plain text: https://secwatch.observer/filing/0001193125-21-251963.txt

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