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Michael Stubblefield

CIK 1776153 · President & CEO · last filed 2025-05-21

Michael Stubblefield is a President & CEO who has filed 31 SEC Form 4 insider transactions across 2 companies since 2019. The most recent filing, for AVTR, was dated May 21, 2025. Across all open-market trades the lifetime net is −$35.2M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $26.6M across reported positions.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

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Disclosed Exposure

$26.59M

Companies

2

Total Filings

31

Lifetime Open-Market Net

-$35.20M

Filer Profile

Reported Address
C/O AVANTOR, INC.
100 MATSONFORD ROAD
RADNOR, PA 19087
Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
AVTR President & CEO 1,764,513 $14.99 $26.46M -$35.20M 27 2025-05-21
IR Director 1,857 $72.48 $134.6K $0 3 2023-08-08

Recent Filings

31 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2025-05-21 AVTR Gift (G) — $0 EDGAR
2025-02-26 AVTR Tax (F) −11,769 -$206.1K EDGAR
2025-02-24 AVTR Mixed +142,558 -$253.9K EDGAR
2024-02-27 AVTR Grant (A) +107,802 $0 EDGAR
2024-02-26 AVTR Mixed +33,196 -$1.61M EDGAR
2024-02-22 AVTR Tax (F) −9,711 -$233.5K EDGAR
2023-08-11 IR Notice (144) −3,774 -$257.6K EDGAR
2023-08-08 IR Exer (M) +1,857 $0 EDGAR
2023-05-30 AVTR Gift (G) — $0 EDGAR
2023-05-19 AVTR Tax (F) −106,200 -$2.15M EDGAR
Showing 1–10 of 31
Page 1 of 4
Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.