What the executives and directors of Idexx Laboratories actually did with their own shares, decoded from three years of SEC Form 4 filings.
The tape: three years of insider trades
Every marker sits at the exact price reported on the Form 4. The line is the monthly median of all prices insiders reported, so the chart needs no market feed; the gray strip is routine flow (vestings, tax withholding, gifts) that headlines love to miscount as selling.
Where the shares went, last 12 months
Every Form 4 movement decomposed: what flowed in (grants, vested equity, purchases) and what flowed out (tax withholding, plan sales, discretionary sales, gifts). Counted in shares, because grants carry no price.
Skin in the game
Directly held shares as reported after each trade, indexed to 100 five years back. Direct holdings only: trust and family-entity positions are per-entity in the filings and do not sum honestly, so this chart refuses to guess. The steps are the trades.
Who holds what
| Insider | Role | Shares held | Buys 12 m | Sales 12 m |
|---|---|---|---|---|
| MAZELSKY JONATHAN JAY President and CEO | CEO | 83.8K | — | $33.8M |
| MCKEON BRIAN P Executive VP & CFO | CFO | 59.2K | — | — |
| AYERS JONATHAN W | Director | 35.7K | — | — |
| Hunt Nimrata Executive Vice President | Officer | 18.1K | — | $14.8M |
| Erickson Michael G Executive Vice President | Officer | 13.4K | — | $3.6M |
| POLEWACZYK JAMES F Executive Vice President | Officer | 11.5K | — | — |
| FENNELL GEORGE Executive Vice President | Officer | 10.7K | — | $7.3M |
| Kingsley Lawrence D | Director | 9,486 | — | — |
| Vandebroek Sophie V. | Director | 9,078 | — | $920K |
| Lane Michael Executive Vice President | Officer | 7,357 | — | $5.3M |
| Underberg Sharon E. EVP, GC & Corporate Secretary | Officer | 7,138 | — | $3.6M |
| Emerson Andrew EVP, CFO and Treasurer | CFO | 3,950 | — | — |
| JUNIUS DANIEL M | Director | 3,561 | — | — |
| Johnson Michael Perkins Executive Vice President | Officer | 2,576 | — | — |
Open-market trade log
| Date | Insider | Type | Shares | Price | Value |
|---|---|---|---|---|---|
| 2026-03-03 | Hunt Nimrata (Officer) | Discretionary sale | 1,758 | $634.57 | $1.1M |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,000 | $662.16 | $662K |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,095 | $651.49 | $713K |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,111 | $654.63 | $727K |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,171 | $653.68 | $765K |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,200 | $661.10 | $793K |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,281 | $650.67 | $834K |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,343 | $656.85 | $882K |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,488 | $655.85 | $976K |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,669 | $652.49 | $1.1M |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 2,589 | $663.04 | $1.7M |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 2,859 | $659.75 | $1.9M |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 2,860 | $657.84 | $1.9M |
| 2026-02-26 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 3,660 | $658.92 | $2.4M |
| 2026-02-26 | Hunt Nimrata (Officer) | Discretionary sale | 2,693 | $661.54 | $1.8M |
| 2026-02-17 | Vandebroek Sophie V. (Director) | Discretionary sale | 519 | $628.56 | $326K |
| 2026-02-17 | Vandebroek Sophie V. (Director) | Discretionary sale | 945 | $628.65 | $594K |
| 2026-02-17 | Erickson Michael G (Officer) | Discretionary sale | 40 | $629.86 | $25K |
| 2026-02-17 | Erickson Michael G (Officer) | Discretionary sale | 204 | $625.24 | $128K |
| 2026-02-17 | Erickson Michael G (Officer) | Discretionary sale | 456 | $623.76 | $284K |
| 2026-02-17 | Erickson Michael G (Officer) | Discretionary sale | 689 | $629.09 | $433K |
| 2026-02-17 | Erickson Michael G (Officer) | Discretionary sale | 1,288 | $626.26 | $807K |
| 2026-02-17 | Erickson Michael G (Officer) | Discretionary sale | 2,694 | $628.22 | $1.7M |
| 2026-02-10 | FENNELL GEORGE (Officer) | Discretionary sale | 40 | $650.32 | $26K |
| 2026-02-10 | FENNELL GEORGE (Officer) | Discretionary sale | 397 | $644.02 | $256K |
| 2026-02-10 | FENNELL GEORGE (Officer) | Discretionary sale | 966 | $648.78 | $627K |
| 2026-02-10 | FENNELL GEORGE (Officer) | Discretionary sale | 1,060 | $647.21 | $686K |
| 2026-02-10 | FENNELL GEORGE (Officer) | Discretionary sale | 1,130 | $643.00 | $727K |
| 2026-02-10 | FENNELL GEORGE (Officer) | Discretionary sale | 2,161 | $645.25 | $1.4M |
| 2026-02-10 | FENNELL GEORGE (Officer) | Discretionary sale | 2,782 | $646.23 | $1.8M |
| 2026-02-10 | FENNELL GEORGE (Officer) | Discretionary sale | 2,809 | $649.26 | $1.8M |
| 2025-11-07 | Hunt Nimrata (Officer) | Discretionary sale | 1,378 | $705.54 | $972K |
| 2025-11-07 | Hunt Nimrata (Officer) | Discretionary sale | 1,465 | $703.73 | $1M |
| 2025-11-07 | Hunt Nimrata (Officer) | Discretionary sale | 1,468 | $704.87 | $1M |
| 2025-11-07 | Hunt Nimrata (Officer) | Discretionary sale | 5,114 | $702.20 | $3.6M |
| 2025-08-22 | SZOSTAK M ANNE (Director) | Discretionary sale | 2,187 | $647.33 | $1.4M |
| 2025-08-12 | Erickson Michael G (Officer) | Discretionary sale | 88 | $649.85 | $57K |
| 2025-08-12 | Erickson Michael G (Officer) | Discretionary sale | 318 | $649.99 | $207K |
| 2025-08-11 | Hunt Nimrata (Officer) | Discretionary sale | 1,200 | $656.53 | $788K |
| 2025-08-08 | Underberg Sharon E. (Officer) | Discretionary sale | 5,450 | $651.60 | $3.6M |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 660 | $639.37 | $422K |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 880 | $636.81 | $560K |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,095 | $626.90 | $686K |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,525 | $628.27 | $958K |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 1,822 | $636.15 | $1.2M |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 3,000 | $632.56 | $1.9M |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 3,397 | $629.82 | $2.1M |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 3,526 | $635.13 | $2.2M |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 6,056 | $630.59 | $3.8M |
| 2025-08-06 | MAZELSKY JONATHAN JAY (CEO) | Discretionary sale | 7,299 | $631.61 | $4.6M |
| 2025-08-06 | Lane Michael (Officer) | Discretionary sale | 300 | $628.89 | $189K |
| 2025-08-06 | Lane Michael (Officer) | Discretionary sale | 2,480 | $627.99 | $1.6M |
| 2025-08-06 | Lane Michael (Officer) | Discretionary sale | 5,631 | $627.56 | $3.5M |
| 2025-08-06 | Hunt Nimrata (Officer) | Discretionary sale | 1,218 | $630.69 | $768K |
| 2025-08-06 | Hunt Nimrata (Officer) | Discretionary sale | 2,907 | $630.91 | $1.8M |
| 2025-08-06 | Hunt Nimrata (Officer) | Discretionary sale | 3,018 | $629.87 | $1.9M |
| 2025-05-21 | SZOSTAK M ANNE (Director) | Discretionary sale | 1,046 | $513.74 | $537K |
| 2025-05-21 | SZOSTAK M ANNE (Director) | Discretionary sale | 1,260 | $512.34 | $646K |
| 2025-05-13 | JUNIUS DANIEL M (Director) | Discretionary sale | 2,683 | $506.41 | $1.4M |
| 2025-05-09 | Vandebroek Sophie V. (Director) | Discretionary sale | 1,279 | $491.34 | $628K |
“Since trade” compares with the latest insider-implied price, not a market quote; this site carries no market data by design.
Filing hygiene
How to read this
A Form 4 transaction code decides everything. P is an open-market purchase and S an open-market sale; those two are the only codes where an insider chose to trade. A is a grant, M an option exercise or vesting, F shares withheld to cover tax, G a gift. Most “insiders dumped billions” headlines are code F and M mechanics.
Sales flagged 10b5-1 run on a plan the insider adopted in advance; since 2023 every Form 4 carries that flag. Buys have historically predicted returns, sales mostly have not, and this page states filings, not advice.