undamentalytics Newsletter

Idexx Laboratories insider trading

Every open-market purchase and sale by Idexx Laboratories's officers, directors and largest shareholders since November 4, 2021, and what the share price did next.

No insider has bought shares on the open market in five years.

Insider purchase Insider sale Marker size reflects trade value. Weekly closes adjusted for splits; may be delayed.
Idexx Laboratories insider open-market trades
DateInsiderTrade SharesPriceValue 1M after 3M after 6M after

From insiders' Form 4 filings with the SEC: open-market purchases and sales only (awards, option exercises and shares withheld for tax are excluded), combined to one line per insider per day. "Plan" marks trades the filing says were made under a pre-set Rule 10b5-1 trading plan, which are scheduled in advance. Price changes run from the close on the trade date; hover a figure for the change relative to the S&P 500. Past moves don't predict future ones.

Does following Idexx Laboratories’s insiders pay?

From February 8, 2010 to September 9, 2026, 33 insiders reported 18 open-market purchases and 255 sales not made under a pre-set plan in Idexx Laboratories. Twelve months after each purchase was reported, the shares were +19.4% against the S&P 500 on average (median +14.7%), over 18 purchases with a full year of prices; 94% beat the index. After sales, the shares moved +6.3% against the index over 12 months (a negative figure means selling was the right call). That rests on fewer than 20 purchases, too few to read much into. Buying each purchase the day after it was reported, an equal amount each, held 12 months or until that insider reported a sale, would have turned $10,000 on February 12, 2010 into $155,085 by November 2, 2026, +17.9% a year. It held shares 54% of the time; the S&P 500 on those same days, with Treasury bills otherwise, made $40,038 (+8.7% a year), and held throughout $94,054 (+14.4%).

$0$50.0k$100k$150k 201020122014201620182020202220242026 $155k$94.1k$40.0k
Copying Idexx Laboratories's insidersS&P 500, same days investedS&P 500, held throughout $10,000 copying every open-market purchase by Idexx Laboratories's insiders from February 12, 2010, before costs and taxes, marked weekly. Uninvested money earns the Treasury bill rate; the portfolio held shares 54% of the time.
Idexx Laboratories: each insider's record
InsiderRolePurchases12 months after their purchasesBeat the S&P 500Sales12 months after their salesLatest report
Ayers Jonathan W Chairman of the Board 0 — — 40 +22.4% (40) May 22, 2023
Henderson Rebecca M Director 0 — — 16 +14.0% (16) February 25, 2021
Szostak M Anne Director 4 +27.4% (4) 100% 12 +7.6% (12) August 26, 2025
Twigge Giovani Senior Vice President 0 — — 16 +18.2% (16) August 5, 2021
Williams Michael J Phd Executive Vice President 0 — — 15 +12.3% (15) August 9, 2016
End William T Director 0 — — 14 +13.1% (14) May 11, 2018
Craig Thomas Director 0 — — 11 +18.1% (11) November 28, 2016
Junius Daniel M Director 1 +38.0% (1) 100% 10 −1.1% (10) May 14, 2025
Lane Michael Executive Vice President 0 — — 11 −7.2% (11) August 8, 2025
Mazelsky Jonathan Jay President and CEO 0 — — 11 −19.7% (10) March 2, 2026
Naqui Ali Corporate Vice President 0 — — 11 +1.6% (11) May 13, 2013
Deady Conan R Corp VP and General Counsel 0 — — 10 −0.1% (10) March 7, 2013
Mckeon Brian P EVP, CFO and Treasurer 0 — — 10 −6.8% (10) February 9, 2024
Turner Kathy V Senior Vice President 0 — — 10 −11.8% (10) February 17, 2023
Vandebroek Sophie V. Director 1 +25.3% (1) 100% 9 +6.3% (8) February 19, 2026
Hunt Nimrata Executive Vice President 0 — — 8 −10.6% (5) March 5, 2026
Polewaczyk James F Executive Vice President 0 — — 8 −18.6% (8) March 7, 2024
Kingsley Lawrence D Director 5 +17.7% (5) 100% 1 — September 9, 2026
Raines Merilee Executive VP & CFO 0 — — 6 +0.1% (6) February 5, 2013
Studer Jacqueline CVP, Gen. Counsel & Secretary 0 — — 6 +11.3% (6) February 27, 2019
Claflin Bruce L. Director 2 +11.8% (2) 100% 3 +3.3% (3) May 20, 2024
Powers Johnny D Executive Vice President 0 — — 4 −5.3% (4) March 6, 2015
Fennell George Executive Vice President 0 — — 3 −9.3% (2) February 11, 2026
Johnson Barry C Director 0 — — 3 +30.5% (3) August 16, 2016
Murray Robert J Director 3 +15.3% (3) 100% 0 — August 8, 2014
Erickson Michael G Executive Vice President 0 — — 2 −35.6% (1) February 19, 2026
Brown William E III Executive Vice President 0 — — 1 +12.0% (1) February 12, 2013
Dupree Thomas J Corporate Vice President 0 — — 1 +9.1% (1) February 22, 2011
Goodspeed William B. Corporate Vice President 0 — — 1 +3.3% (1) April 28, 2011
Meyaard Daniel V Corporate Vice President 1 +18.3% (1) 100% 0 — February 11, 2010
Underberg Sharon E. EVP, GC & Corporate Secretary 0 — — 1 −38.7% (1) August 12, 2025
Vumbacco Joseph V Director 1 −0.7% (1) 0% 0 — May 27, 2010
Wallen William C Senior VP & CSO 0 — — 1 +22.3% (1) February 8, 2010

Moves are the shares’ return including dividends minus the S&P 500’s, from the close on the first trading day after each report; the number of trades with a finished 12-month window is in brackets. Green means the trade went the insider’s way (a purchase ahead of the index, a sale followed by the shares trailing it). A trade reported both by a director or officer and by a fund or company they are linked to counts once here, under the person. Purchases count only where the share price actually traded was at least $5. These figures describe what the shares did, not why anyone traded. Insiders across all companies.

When several insiders traded Idexx Laboratories

Months when 2 or more insiders became net buyers, or 3 or more net sellers, of Idexx Laboratories in reports dated in the 91 days before the month end, and how the stock did against the S&P 500 from that month end. After the 2 buying crowds with six months of prices, it averaged +20.1% against the index. After 20 selling crowds, +5.0%. One company's history is too short to judge by; the test across every company is the better guide.

MonthCrowd3 months on, vs S&P 5006 months12 months
February 27, 20263 selling−24.8%−28.2%not yet
May 30, 20253 selling+16.3%+30.0%−23.1%
February 29, 20244 selling−16.3%−25.9%−38.2%
September 29, 20233 selling+15.3%−2.9%−21.5%
May 31, 20234 selling+1.6%−9.2%−21.1%
December 30, 20224 selling+12.1%+4.0%+6.7%
December 31, 20193 selling+11.4%+30.6%+72.6%
February 28, 20194 selling+17.8%+30.7%+12.3%
June 29, 20183 selling+6.9%−7.7%+15.7%
December 30, 20163 selling+26.7%+26.5%+12.0%
August 31, 20165 selling+2.5%+19.7%+21.8%
February 29, 20163 selling+13.9%+37.1%+73.3%

Colours show whether the crowd was right: green when buyers were followed by a rise above the index, or sellers by a fall below it. Latest 12 of 22. Total returns from the month end; past patterns are not a forecast.

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