WAUN THOMAS J. SR. 4

4 · ADVANCED DRAINAGE SYSTEMS, INC. · Filed May 21, 2026

AI-generated summary of this filing

Updated May 21, 2026

Advanced Drainage (WMS) EVP Waun Thomas Receives Award, Sells Shares

What Happened

Waun Thomas Jr. (listed as Waun Thomas J. Sr.), EVP, International, received a grant of 4,555 shares (performance-based units) reported as acquired on 2026-05-19 (reported value $0). To satisfy tax obligations tied to the vesting, 117 shares were withheld/sold on 2026-05-19 at $131.59 ($15,396) and 100 shares were withheld/sold on 2026-05-20 at $136.83 ($13,683), a total of 217 shares disposed for $29,079.
The award is performance-based (granted under the company’s Omnibus Incentive Plan) and includes dividend equivalents. The disposals were tax-withholding actions (routine), not open-market “sell” decisions signaling investment views.

Key Details

Transaction dates & prices:
- 2026-05-19: 117 shares withheld at $131.59 — $15,396.
- 2026-05-20: 100 shares withheld at $136.83 — $13,683.
- 2026-05-19: 4,555 shares awarded (performance units), $0 reported price.
Total withheld/disposed: 217 shares for ~$29,079.
Footnotes of note:
- F1: Shares were withheld to satisfy tax obligations upon vesting.
- F3: The 4,555 shares reflect performance-based units earned for the period ended March 31, 2026 and include 63 dividend-equivalent shares paid in stock.
- F2/F4: Filing also references 89 ESPP shares exempt under Rule 16b-3(c) and current allocation under KSOP.
Shares owned after the transactions: not specified in the provided filing excerpt.
Filing timeliness: Report filed 2026-05-21, within days of the reported transactions; not flagged as a late filing here.

Context

These transactions are primarily a compensation vesting event (award of performance units) with routine tax-withholding disposals — common when restricted or performance shares vest. Such withholding sales are procedural and do not necessarily indicate the insider is choosing to sell stock for investment reasons.

Form 4

Period: 2025-05-19

EVP, International

Transactions

Holdings

Footnotes (4)

[F1]Represents shares withheld to satisfy Reporting Person's tax obligations in connection with the vesting of shares of restricted common stock of the Issuer.
[F2]Includes 89 shares of common stock acquired under the Advanced Drainage Systems, Inc. Employee Stock Purchase Plan, exempt under Rule 16b-3(c).
[F3]Reflects grant of performance-based units, originally granted pursuant to the Issuer's 2017 Omnibus Incentive Plan, earned after the Issuer determined that certain performance goals for the performance period ended March 31, 2026 had been met. Total includes dividend equivalents in the amount of 63 shares, which dividend equivalents are settled in common stock
[F4]Represents current allocation under KSOP.

Signature

/s/ Thomas J. Waun, Sr., by Scott A. Cottrill as attorney-in-fact|2026-05-21

1 file