Avantor, Inc.
A maker of mission-critical materials for labs and biopharma, Avantor sells high-purity chemicals (J.T. Baker), tubing (Masterflex), and medical-grade silicones (NuSil), delivered worldwide through its VWR channel. Its roots trace to 1904, when chemist John Townsend Baker began producing purer lab reagents; NuSil and the 1852-founded VWR distributor later joined the fold. Fun fact: in a 1993 silicone shortage, NuSil cloned discontinued materials so device makers could keep producing long-term implants.
Granted 756.5K · Bought 15.0K · Sold 141.3K
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| Insider | Stake change | Holds now | Granted / vested | Bought | Sold |
|---|---|---|---|---|---|
| Stubblefield MichaelPresident & CEO, Director · 30 transactions | — | 3.84Mas of May 2025 | 756.5K | 15.0K | 141.3K |
| Gupta RajivDirector · 6 transactions | -32% | 1.06Mas of Apr 2022 | 1.2K | — | 400.0K |
| Mehra Sanjeev KDirector · 4 transactions | — | 866.5K | 33.4K | 475.0K | — |
| Ligner EmmanuelPresident and CEO, Director · 3 transactions | — | 767.1K | 679.6K | 87.5K | — |
| Summe Gregory LDirector · 13 transactions | — | 483.4K | 68.6K | 400.0K | — |
| Jones R. BrentEVP, Chief Financial Officer · 7 transactions | — | 419.8K | 429.8K | — | — |
| Walker CoreyPresident, VWR Dist. & Servs. · 6 transactions | +445.6% | 384.5K | 352.4K | — | — |
| Gourdier BenoitEVP, Bioscience & Medtech · 10 transactions | — | 362.9K | 375.4K | — | — |
| Szlosek Thomas AEVP & CFO · 14 transactions | — | 254.4Kas of May 2023 | 92.6K | 12.5K | — |
| Blenn MaryEVP, Chief Operating Officer · 2 transactions | — | 253.4K | 253.4K | — | — |
| Sokenu ClaudiusEVP, Chief Legal & Compliance · 10 transactions | — | 252.4K | 266.3K | — | — |
| Hankamer BrittanyEVP, Chief HR Officer · 17 transactions | — | 249.0K | 231.2K | — | — |
| Peacock Jonathan MDirector · 6 transactions | +30.5% | 219.8Kas of May 2025 | 43.3K | 8.1K | — |
| Couturier ChristopheEVP, AMEA · 45 transactions | +91.9% | 211.3Kas of Aug 2025 | 290.0K | — | 139.5K |
| Vanderhaegen FredericEVP, Americas and Europe · 18 transactions | -25% | 160.7Kas of Aug 2023 | 160.1K | — | 204.8K |
| Lucier Gregory TDirector · 4 transactions | — | 152.7K | 34.0K | 60.0K | — |
| Brellier LudovicEVP, Bioscience & Medtech · 1 transaction | — | 146.6K | 146.6K | — | — |
| Eck Steven WSVP & Chief Accounting Officer · 33 transactions | +825.8% | 131.0K | 156.5K | — | 24.2K |
| Wondrasch MichaelEVP & CIO · 2 transactions | -15.2% | 96.1Kas of Feb 2023 | — | — | — |
| Miller JustinEVP & General Counsel · 11 transactions | +7.9% | 93.3Kas of May 2023 | 42.8K | — | — |
| Brophy GerardEVP, Biopharma Production · 22 transactions | -61.4% | 89.0Kas of May 2023 | 133.6K | — | 114.0K |
| Bramwell JamesEVP Sales, Customer Excellence · 19 transactions | +8.4% | 86.6Kas of Feb 2025 | 48.3K | — | 15.6K |
| Severino MichaelDirector · 6 transactions | +397.3% | 85.8K | 68.6K | — | — |
| Massaro Joseph RDirector · 8 transactions | — | 77.4K | 69.3K | 8.1K | — |
| Lewis SheriEVP, Global Ops & Supply Chain · 8 transactions | +5.7% | 70.7Kas of Dec 2023 | 22.0K | — | — |
| Murthy MalaDirector · 7 transactions | — | 69.5K | 69.5K | — | — |
| Stone Randy LeeEVP, Laboratory Solutions · 3 transactions | — | 68.1Kas of Apr 2024 | 74.0K | — | — |
| Andres JuanDirector · 5 transactions | +195.1% | 65.5Kas of May 2025 | 43.3K | — | — |
| Dingemans SimonDirector · 3 transactions | — | 56.5K | 31.5K | 25.0K | — |
| Kang LanDirector · 6 transactions | +1200.7% | 52.3Kas of May 2025 | 43.3K | 5.0K | — |
| Makin LouiseDirector · 3 transactions | — | 47.1K | 47.1K | — | — |
| Carethers JohnDirector · 5 transactions | +1687.8% | 45.9Kas of May 2025 | 43.3K | — | — |
| Sahin KittyEVP, Strategy&Corp Development · 5 transactions | — | 42.3Kas of Jul 2024 | 24.5K | — | — |
| Henson MeghanEVP, Chief HR Officer · 7 transactions | +52.5% | 40.2Kas of Feb 2023 | 20.5K | — | — |
| Shaw ChristiDirector · 3 transactions | +95.5% | 36.3Kas of May 2023 | 17.7K | — | — |
| Murray Mark ChristopherEVP, Biomaterials & AT · 1 transaction | -4.7% | 18.7Kas of Jan 2022 | — | — | — |
| Holt Matthew S.Director · 2 transactions | — | 7.9Kas of May 2022 | 7.9K | — | — |
Select a row to see that insider’s individual transactions. Sum of the holdings confirmed in the 12 months before this insider's last filing. A Form 4 reports a holding per line — held directly, or through a named trust, partnership or foundation, and in each share class separately — never a person’s total. Lines not restated in that time are left out and shown apart: an active filer restates what they still hold, so a line they did not restate is more often an entity since renamed, whose shares a successor line reports too. An amber marker means some were left out.
Net open-market activity over the last 5 years: +56.7K shares. Grants, option exercises and tax withholding are excluded — they are compensation mechanics, not decisions to buy or sell.