IDXX insider ownership: who sold, why, and what they still hold

Who	Shares	Price	% of total stake	Total stake after	Trade date	Filed
Lawrence Kingsley Director	2,203	$532.08	19%	9.6K	Sep 4, 2026	Sep 9, 2026

What stands out

Jonathan Mazelsky sold 28% of vested holdings: 23K shares for $15.3M, none under a disclosed plan.Largest sale, Feb 26, 2026

Four insiders sold $21.4M with no disclosed plan: Nimrata Hunt ($9.5M), George Fennell ($7.3M) and Michael Erickson ($3.4M), plus 1 more. The filings don't state a reason.Nimrata Hunt: largest such sale, Nov 7, 2025 · George Fennell: largest such sale, Feb 10, 2026 · Michael Erickson: largest such sale, Feb 17, 2026

Lawrence Kingsley sold 2.2K shares (24% of starting holdings), but 2.5K more shares were added, so the stake grew (from 9.2K to 9.6K).Largest sale, Sep 4, 2026

Percentages cover 15 of 20 officers and directors. 5 are left out

Left out: Nimrata Hunt, Michael Erickson and George Fennell (most of their shares vested during the period, so a percentage would mislead); Sam Samad and Joseph Hooley (held no vested shares at the start).

Disclosed company stock is not an insider's whole wealth.

Who sold, and how much of their stake

Officers and directors, past 12 months. Each bar is the insider's vested stake at the start of the period (Oct 8, 2025). The gold part is what they sold.

SoldRest of starting stakeAdded during the period

Jonathan Mazelsky

President and CEO, Director

Sold 28%, but 26K shares were added (mostly vesting), so the stake grew

28% · $15.3MNo plan disclosed

Nimrata Hunt

Executive Vice President

Sold 43% of the shares held or received (after tax withholding) during the period†. No bar against the starting stake: most of these shares arrived during the period.

$9.5MNo plan disclosed

George Fennell

Executive Vice President

Sold 52% of the shares held or received (after tax withholding) during the period†. No bar against the starting stake: most of these shares arrived during the period.

$7.3MNo plan disclosed

Michael Erickson

Executive Vice President

Sold 26% of the shares held or received (after tax withholding) during the period†. No bar against the starting stake: most of these shares arrived during the period.

$3.4MNo plan disclosed

Lawrence Kingsley

Director

Sold 24%, but 2.5K shares were added (mostly vesting), so the stake grew

24% · $1.2MNo plan disclosed

All 6 sellers

Selling by month

Officers and directors, Oct 2025 to Oct 2026. Each sale is counted once: under a disclosed plan, else to cover taxes, else no plan disclosed.

Disclosed planTo cover taxesNo plan disclosed

Common questions

Is the Idexx Laboratories CEO selling stock?

Yes. Jonathan Mazelsky sold 23K shares ($15.3M, 28% of starting holdings) in the past 12 months, none of it under a trading plan disclosed in the filings.

Why are Idexx Laboratories insiders selling?

Filings rarely give a reason, and we don't guess at one. What they show is how the sales were made: 0% of sales by value ran under 10b5-1 trading plans disclosed in the filings and 100% had no disclosed plan. A trading plan schedules sales in advance.

Are any Idexx Laboratories insiders buying?

No. Officers and directors reported no purchases in the past 12 months.

How much of their stake did Idexx Laboratories insiders sell?

About 20% overall. As a group they ended with more shares than they started with. That covers the 12 months to Oct 8, 2026 and counts vested shares reported on SEC Forms 3, 4 and 5, which is not an insider's whole wealth.

The evidence

Who sold6 officers and directors: amount, % of holdings, trading plan

Who sold	Amount	% of holdings	Trading plan
Jonathan Mazelsky President and CEO, Director	$15.3M 23K shares	28%	No plan disclosed
Nimrata Hunt Executive Vice President	$9.5M 14K shares	43%† i † Most of the shares Nimrata Hunt sold arrived during the period, so this is shares sold as a share of the 18K held at the start plus the 15K received, less 1.2K withheld by the company for taxes.	No plan disclosed
George Fennell Executive Vice President	$7.3M 11K shares	52%† i † Most of the shares George Fennell sold arrived during the period, so this is shares sold as a share of the 8.3K held at the start plus the 14K received, less 483 withheld by the company for taxes.	No plan disclosed
Michael Erickson Executive Vice President	$3.4M 5.4K shares	26%† i † Most of the shares Michael Erickson sold arrived during the period, so this is shares sold as a share of the 11K held at the start plus the 10K received, less 974 withheld by the company for taxes.	No plan disclosed
Lawrence Kingsley Director	$1.2M 2.2K shares	24%	No plan disclosed
Sophie Vandebroek Director	$920K 1.5K shares	16%	No plan disclosed

The full ownership picture20 of 20 insiders fully reconciled · 19 officers and directors

Vested shares across all share classes, held directly and through trusts, LLCs and family members, as reported on SEC Forms 3, 4 and 5. Unvested awards and options are never counted as owned shares.

Insider

Held Oct 8, 2025

Sold

Held Oct 8, 2026

Still held

Jonathan Mazelsky

Minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

President and CEO, Director

82K

−23K

84K

+1.6%

Vesting, gifts, unvested awards and holding lines for Jonathan Mazelsky

+26Kshares vested or exercised

0gifted (net of own trusts)

−915withheld by the company for taxes

3.2K → 15Kunvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	82,443	83,803

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
806	$124.00	Feb 13, 2024	$329K
21,335	$560.56	Feb 13, 2034	$0
178	$560.56	Feb 13, 2034	$0
25,932	$459.76	Feb 12, 2035	$1.9M
217	$459.76	Feb 12, 2035	$16K

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Reconciliation: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Nimrata Hunt

Minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer). Additional holdings last reported more than 3 years ago are shown separately and excluded from totals.

Executive Vice President

18K

−14K

18K

not meaningful

Vesting, gifts, unvested awards and holding lines for Nimrata Hunt

+15Kshares vested or exercised

0gifted (net of own trusts)

−1.2Kwithheld by the company for taxes

3K → 4.6Kunvested awards, start → end

Additional holdings last reported more than 3 years ago are shown separately and excluded from totals.

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	18,033	18,141
jointly with spouse	Common Stock	160	160

Additional holdings last reported Feb 9, 2023, not confirmed since: 160 shares. Not included in any total or percentage on this page.

Spouse, Common Stock: 160 shares, last reported Feb 9, 2023

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
1,604	$505.53	Feb 13, 2032	$43K
5,407	$560.56	Feb 14, 2034	$0
178	$560.56	Feb 13, 2034	$0
6,320	$459.76	Feb 12, 2035	$457K
217	$459.76	Feb 12, 2035	$16K
4,625	$617.20	Feb 11, 2036	$0
162	$617.20	Feb 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Reconciliation: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Michael Erickson

Minor difference of 17 shares. Difference is under 0.5% of holdings. Unvested RSUs stated in footnotes are excluded from owned shares.

Executive Vice President

11K

−5.4K

15K

not meaningful

Vesting, gifts, unvested awards and holding lines for Michael Erickson

+10Kshares vested or exercised

0gifted (net of own trusts)

−974withheld by the company for taxes

4.2K → 8.1Kunvested awards, start → end

Unvested RSUs stated in footnotes are excluded from owned shares.

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	11,287	14,908

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
4,826	$206.94	Feb 13, 2029	$1.6M
4,008	$288.78	Feb 13, 2030	$975K
2,468	$544.08	Feb 13, 2031	$0
3,078	$505.53	Feb 13, 2032	$82K
2,558	$497.43	Feb 13, 2033	$89K
201	$497.43	Feb 13, 2033	$7K
5,407	$560.56	Feb 13, 2034	$0
178	$560.56	Feb 13, 2034	$0
6,320	$459.76	Feb 12, 2035	$457K
217	$459.76	Feb 12, 2035	$16K
13,667	$617.20	Feb 11, 2036	$0
162	$617.20	Feb 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Reconciliation: minor difference of 17 shares. Difference is under 0.5% of holdings.

Sophie Vandebroek

Additional holdings last reported more than 3 years ago are shown separately and excluded from totals.

Director

9.3K

−1.5K

9.1K

97%

Vesting, gifts, unvested awards and holding lines for Sophie Vandebroek

+1.2Kshares vested or exercised

0gifted (net of own trusts)

257 → 234unvested awards, start → end

Additional holdings last reported more than 3 years ago are shown separately and excluded from totals.

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	1,167	905
Sophie V. Vandebroek Revocable Trust	Common Stock	8,173	8,173

Additional holdings last reported Feb 12, 2021, not confirmed since: 6,000 shares. Not included in any total or percentage on this page.

Sophie Vandebroek Revocable Trust, Common Stock: 6,000 shares, last reported Feb 12, 2021

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
609	$476.87	May 5, 2034	$34K
600	$486.61	May 6, 2035	$27K
525	$533.92	May 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Lawrence Kingsley

Director

9.2K

−2.2K

9.6K

+3.7%

Vesting, gifts, unvested awards and holding lines for Lawrence Kingsley

+2.5Kshares vested or exercised

0gifted (net of own trusts)

339 → 309unvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	9,229	9,568

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
609	$476.87	May 5, 2034	$34K
195	$476.87	May 5, 2034	$11K
600	$486.61	May 6, 2035	$27K
192	$486.61	May 6, 2035	$9K
525	$533.92	May 11, 2036	$0
168	$533.92	May 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

George Fennell

New Form 3 filed 2024-01-05; earlier filings set aside.

Executive Vice President

8.3K

−11K

10K

not meaningful

Vesting, gifts, unvested awards and holding lines for George Fennell

+14Kshares vested or exercised

0gifted (net of own trusts)

−483withheld by the company for taxes

2.3K → 2Kunvested awards, start → end

New Form 3 filed 2024-01-05; earlier filings set aside.

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	8,347	10,433

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
5,302	$141.60	Feb 13, 2027	$2.1M
706	$141.60	Feb 13, 2027	$276K
4,437	$178.26	Feb 13, 2028	$1.6M
560	$178.26	Feb 13, 2028	$198K
4,826	$206.94	Feb 13, 2029	$1.6M
483	$206.94	Feb 13, 2029	$157K
4,008	$299.78	Feb 13, 2030	$931K
1,805	$544.08	Feb 13, 2031	$0
183	$544.08	Feb 13, 2031	$0
1,768	$505.53	Feb 13, 2032	$47K
197	$505.53	Feb 13, 2032	$5K
1,454	$497.43	Feb 13, 2033	$50K
201	$497.43	Feb 13, 2033	$7K
2,408	$560.56	Feb 13, 2034	$0
178	$560.56	Feb 13, 2034	$0
3,415	$459.76	Feb 12, 2035	$247K
217	$459.76	Feb 12, 2035	$16K
3,384	$617.20	Feb 11, 2036	$0
162	$617.20	Feb 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Michael Lane

Minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer). Unvested RSUs stated in footnotes are excluded from owned shares.

Executive Vice President

7.7K

8.2K

no sales

Vesting, gifts, unvested awards and holding lines for Michael Lane

+1.1Kshares vested or exercised

0gifted (net of own trusts)

−221withheld by the company for taxes

3K → 4.8Kunvested awards, start → end

Unvested RSUs stated in footnotes are excluded from owned shares.

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	7,132	7,657
Spouse	Common Stock	592	592

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
5,407	$560.56	Feb 13, 2034	$0
178	$560.56	Feb 13, 2034	$0
6,320	$459.76	Feb 12, 2035	$457K
217	$459.76	Feb 12, 2035	$16K
5,361	$617.20	Feb 11, 2036	$0
162	$617.20	Feb 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Reconciliation: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Sharon Underberg

Minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

EVP, GC & Corporate Secretary

6.3K

7.1K

no sales

Vesting, gifts, unvested awards and holding lines for Sharon Underberg

+1Kshares vested or exercised

0gifted (net of own trusts)

−251withheld by the company for taxes

2.2K → 2.3Kunvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	6,339	7,138

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
3,856	$560.56	Feb 13, 2034	$0
178	$560.56	Feb 13, 2034	$0
4,504	$459.76	Feb 12, 2035	$326K
217	$459.76	Feb 12, 2035	$16K
3,738	$617.20	Feb 11, 2036	$0
162	$617.20	Feb 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Reconciliation: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Andrew Emerson

Minor difference of 39 shares. Small increase from an employee stock purchase plan. Includes unvested RSUs, amount not disclosed. Small increase from an employee stock purchase plan.

EVP, CFO and Treasurer

3.9K

4.4K

no sales

Vesting, gifts, unvested awards and holding lines for Andrew Emerson

+721shares vested or exercised

0gifted (net of own trusts)

−209withheld by the company for taxes

1.4K → 2Kunvested awards, start → end

Includes unvested RSUs, amount not disclosed.
Small increase from an employee stock purchase plan. Filing

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct includes unvested RSUs, amount not disclosed	Common Stock	3,871	4,421

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
925	$178.26	Feb 13, 2028	$327K
586	$206.94	Feb 13, 2029	$191K
515	$206.94	Feb 13, 2029	$167K
662	$288.78	Feb 13, 2030	$161K
229	$288.78	Feb 13, 2030	$56K
230	$544.08	Feb 13, 2031	$0
183	$544.08	Feb 13, 2031	$0
546	$505.53	Feb 13, 2032	$14K
182	$505.53	Feb 13, 2032	$5K
703	$497.43	Feb 13, 2033	$24K
217	$497.43	Feb 13, 2033	$8K
598	$560.56	Feb 13, 2034	$0
178	$560.56	Feb 13, 2034	$0
4,383	$459.76	Feb 12, 2035	$317K
217	$459.76	Feb 12, 2035	$16K
4,270	$617.20	Feb 11, 2036	$0
162	$617.20	Feb 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Reconciliation: minor difference of 39 shares. Small increase from an employee stock purchase plan.

Daniel Junius

Director

3.3K

3.6K

no sales

Vesting, gifts, unvested awards and holding lines for Daniel Junius

+257shares vested or exercised

0gifted (net of own trusts)

257 → 234unvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	3,304	3,561

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
609	$476.87	May 5, 2034	$34K
600	$486.61	May 6, 2035	$27K
525	$533.92	May 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Michael Johnson

Minor difference of 34 shares. Small increase from an employee stock purchase plan. Small increase from an employee stock purchase plan.

Executive Vice President

2.4K

2.8K

no sales

Vesting, gifts, unvested awards and holding lines for Michael Johnson

+573shares vested or exercised

0gifted (net of own trusts)

−178withheld by the company for taxes

2.5K → 2.7Kunvested awards, start → end

Small increase from an employee stock purchase plan. Filing

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	2,365	2,795

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
3,132	$560.56	Feb 13, 2034	$0
178	$560.56	Feb 13, 2034	$0
3,657	$459.76	Feb 12, 2035	$264K
217	$459.76	Feb 12, 2035	$16K
3,207	$617.20	Feb 11, 2036	$0
162	$617.20	Feb 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Reconciliation: minor difference of 34 shares. Small increase from an employee stock purchase plan.

Stuart Essig

Director

2.2K

no sales

Vesting, gifts, unvested awards and holding lines for Stuart Essig

0shares vested or exercised

0gifted (net of own trusts)

257 → 491unvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	2,236	2,236

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
609	$476.87	May 5, 2034	$34K
600	$486.61	May 6, 2035	$27K
525	$533.92	May 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Anne Szostak

Director

2.1K

2.3K

no sales

Vesting, gifts, unvested awards and holding lines for Anne Szostak

+257shares vested or exercised

0gifted (net of own trusts)

257 → 0unvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	262	519
Trust of M. Anne Szostak	Common Stock	1,542	1,542
O'Hanian-Szostak Family Foundation	Common Stock	259	259

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
609	$476.87	May 5, 2034	$34K
600	$486.61	May 6, 2035	$27K

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Michael Schreck

Minor difference of 50 shares. Small increase from an employee stock purchase plan. Small increase from an employee stock purchase plan.

Executive Vice President

3.1K

no sales

Vesting, gifts, unvested awards and holding lines for Michael Schreck

+2Kshares vested or exercised

0gifted (net of own trusts)

−876withheld by the company for taxes

3.8K → 4.6Kunvested awards, start → end

Small increase from an employee stock purchase plan. Filing

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	1,956	3,089

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
744	$398.49	Aug 31, 2030	$99K
2,769	$544.08	Feb 13, 2031	$0
324	$544.08	Feb 13, 2031	$0
3,952	$505.53	Feb 13, 2032	$105K
197	$505.53	Feb 13, 2032	$5K
4,765	$497.43	Feb 13, 2033	$165K
201	$497.43	Feb 13, 2033	$7K
5,407	$560.56	Feb 13, 2034	$0
178	$560.56	Feb 13, 2034	$0
6,320	$459.76	Feb 12, 2035	$457K
217	$459.76	Feb 12, 2035	$16K
4,625	$617.20	Feb 11, 2036	$0
162	$617.20	Feb 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Reconciliation: minor difference of 50 shares. Small increase from an employee stock purchase plan.

Bruce Claflin

Director

1.7K

no sales

Vesting, gifts, unvested awards and holding lines for Bruce Claflin

0shares vested or exercised

0gifted (net of own trusts)

1.1K → 2.5Kunvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	161	161
Claflin Family Trust	Common Stock	1,560	1,560

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
609	$476.87	May 5, 2034	$34K
600	$486.61	May 6, 2035	$27K
525	$533.92	May 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Martin Smith

Minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Executive Vice President

1.4K

2.2K

no sales

Vesting, gifts, unvested awards and holding lines for Martin Smith

+1Kshares vested or exercised

0gifted (net of own trusts)

−302withheld by the company for taxes

2.9K → 4.8Kunvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	1,434	2,157

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
5,407	$560.56	Feb 13, 2034	$0
178	$560.56	Feb 13, 2034	$0
6,320	$459.76	Feb 12, 2035	$457K
217	$459.76	Feb 12, 2035	$16K
5,361	$617.20	Feb 11, 2036	$0
162	$617.20	Feb 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Reconciliation: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Irene Britt

Director

208

no sales

Vesting, gifts, unvested awards and holding lines for Irene Britt

0shares vested or exercised

0gifted (net of own trusts)

519 → 1.3Kunvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	208	208

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
609	$476.87	May 5, 2034	$34K
600	$486.61	May 6, 2035	$27K
525	$533.92	May 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Karen Peacock

Director

102

no sales

Vesting, gifts, unvested awards and holding lines for Karen Peacock

+101shares vested or exercised

0gifted (net of own trusts)

0 → 234unvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	1	102

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
231	$727.97	Nov 30, 2035	$0
525	$533.92	May 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

Joseph Hooley

Director

325

no sales

Vesting, gifts, unvested awards and holding lines for Joseph Hooley

+158shares vested or exercised

0gifted (net of own trusts)

158 → 234unvested awards, start → end

Held through	Share class	Oct 8, 2025	Oct 8, 2026
Direct	Common Stock	0	325

Stock options (not counted as shares):

Options held	Strike price	Expires	Intrinsic value (estimate)
364	$647.09	Aug 31, 2035	$0
525	$533.92	May 11, 2036	$0

Estimate: options held × ($532.08 − strike price), using the most recent insider trade price on Form 4 (Sep 4, 2026), not a market close.

20 of 20 insiders fully reconciled: starting holdings plus reported transactions match ending holdings (11 exactly, 9 with a minor or footnoted difference). Percentages cover 15 of 20 officers and directors. Left out: Nimrata Hunt, Michael Erickson and George Fennell (most of their shares vested during the period, so a percentage would mislead); Sam Samad and Joseph Hooley (held no vested shares at the start). "Still held" compares ending with starting vested shares; a plus sign means the holding grew.

What explains the selling$37.7M of sales by plan status, purpose, seller and month

Officer and director open-market sales: $37.7M across 57,585 shares. Plan status and stated purpose are separate questions, and a sale can have both.

By plan status

No plan disclosed · $37.7M

Sales with no 10b5-1 plan and no tax reference in the filing. $15.3M of it is Jonathan Mazelsky. No plan disclosed is a statement about the filing, not about why the sale happened. Largest such sale: Nimrata Hunt, Nov 7, 2025

Taxes

5,563 shares ($3.4M) were withheld by the company for taxes, which isn't a market sale.

Seller	Shares sold	Proceeds	Under a disclosed plan	Share of total	Sales dates
Jonathan Mazelsky President and CEO, Director	23K	$15.3M	0%	41%	Feb 26, 2026 to Feb 26, 2026
Nimrata Hunt Executive Vice President	14K	$9.5M	0%	25%	Nov 7, 2025 to Mar 3, 2026
George Fennell Executive Vice President	11K	$7.3M	0%	19%	Feb 10, 2026 to Feb 10, 2026
Michael Erickson Executive Vice President	5.4K	$3.4M	0%	9%	Feb 17, 2026 to Feb 17, 2026
Lawrence Kingsley Director	2.2K	$1.2M	0%	3%	Sep 4, 2026 to Sep 4, 2026
Sophie Vandebroek Director	1.5K	$920K	0%	2%	Feb 17, 2026 to Feb 17, 2026

Sales by month

Month	Sale proceeds	Disclosed plan	To cover taxes	No plan disclosed
Oct 2025	$0	$0	$0	$0
Nov 2025	$6.6M	$0	$0	$6.6M
Dec 2025	$0	$0	$0	$0
Jan 2026	$0	$0	$0	$0
Feb 2026	$28.7M	$0	$0	$28.7M
Mar 2026	$1.1M	$0	$0	$1.1M
Apr 2026	$0	$0	$0	$0
May 2026	$0	$0	$0	$0
Jun 2026	$0	$0	$0	$0
Jul 2026	$0	$0	$0	$0
Aug 2026	$0	$0	$0	$0
Sep 2026	$1.2M	$0	$0	$1.2M
Oct 2026	$0	$0	$0	$0

Is this normal? Selling year by year5 earlier years to compare with

Less than usual: about half of the 5-year average. 6 insiders sold; the average is 8 a year.

12 months ending	Shares sold	Insiders who sold	Proceeds
Oct 8, 2026 Latest 12 months	58K	6	$37.7M
Oct 8, 2025 1 year earlier	74K	9	$43.6M
Oct 8, 2024 2 years earlier	72K	7	$40.3M
Oct 9, 2023 3 years earlier	129K	8	$60.6M
Oct 9, 2022 4 years earlier	50K	3	$31.5M
Oct 9, 2021 5 years earlier	266K	13	$140M

Open-market sales (Form 4 code S) by people who were officers or directors, in split-adjusted shares. Earlier years include people who have since left. A sale that an outside holder also reports (a family trust, a fund) is counted with outside holders in every year. Shares, not dollars, are compared, so a change in the stock price doesn't look like a change in selling. Years the filings don't fully cover are shown but left out of the average.

Known gaps and uncertaintyEvery officer and director reconciles

Every officer and director reconciles for this period.

Jonathan Mazelsky: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Nimrata Hunt: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Michael Erickson: minor difference of 17 shares. Difference is under 0.5% of holdings.

Michael Lane: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Sharon Underberg: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Andrew Emerson: minor difference of 39 shares. Small increase from an employee stock purchase plan.

Michael Johnson: minor difference of 34 shares. Small increase from an employee stock purchase plan.

Michael Schreck: minor difference of 50 shares. Small increase from an employee stock purchase plan.

Martin Smith: minor difference of 21 shares. Difference is stated in footnotes (unreported vesting, exempt acquisition or transfer).

Inferred rename: "Spouse" is treated as the same holder as "Trust", because the old name was never reported again and the new one opened with the same balance (1,400 shares). Old name, new name

Inferred rename: "Charitable Remainder Unitrust" is treated as the same holder as "Charitable Remainder Trust", because the old name was never reported again and the new one opened with the same balance (26,860 shares). Old name, new name

Inferred typo: the share class "Commmon Stock" is treated as the same class as "Common Stock" on 1 holding line, because the two spellings are nearly identical and each balance carried over exactly. Example (Robert Murray, 8,000 shares): old title, new title

External context: we only cite outside events when a documented connection exists. None is shown for this period.

Sources and methodology1,459 filings from SEC EDGAR, and how we read them

All 1,459 Forms 3, 4 and 5 filed for Idexx Laboratories (SEC CIK 874716) from Jan 31, 2003 to Sep 9, 2026, retrieved from SEC EDGAR on Oct 8, 2026. Prices are the ones reported in each filing, often weighted averages. 19 older filings exist only on paper and could not be read.

Probable 2-for-1 stock split on or before Dec 10, 2007 (first filing that shows post-split balances). Splits aren't reported as transactions; 10 holding lines changed by exactly this ratio, so earlier share counts are restated.

Probable 2-for-1 stock split on or before Jun 15, 2015 (split date stated in a footnote). Splits aren't reported as transactions; 10 holding lines changed by exactly this ratio, so earlier share counts are restated.

Holdings. Each holding line (a share class plus an owner, such as a trust or LLC) carries its last reported balance forward. Entities first reported during the period start at zero, so transfers between an insider's own trusts don't count as selling. Lines not reported for three years or more are listed separately and left out of totals.

Sales. A sale counts as under a 10b5-1 plan if its footnote cites one or the filing's Rule 10b5-1 box is checked, and as tax-related if its footnote cites tax obligations or sell-to-cover. Shares withheld by the company for taxes are listed separately. Sales with neither attribute are labeled "no plan disclosed".

Full methodology

Former or inactive filers (37)No filing in 18 months; last reported balances, not in any total

Name	Last filed	Last reported balance
Brian McKeon	Feb 18, 2025	49,600 shares, last reported balance as of Feb 14, 2025
Jonathan Ayers	Sep 9, 2024	577,830 shares, last reported balance as of Sep 6, 2024
Asha COLLINS	May 8, 2024	779 shares, last reported balance as of May 6, 2024
James Polewaczyk	Mar 7, 2024	10,711 shares, last reported balance as of Mar 6, 2024
Kathy Turner	Feb 17, 2023	7,480 shares, last reported balance as of Feb 16, 2023
Giovani Twigge	Feb 25, 2022	20,329 shares, last reported balance as of Feb 23, 2022
Rebecca Henderson	Feb 25, 2021	14,696 shares, last reported balance as of Feb 23, 2021
Jacqueline Studer	Feb 27, 2019	4,389 shares, last reported balance as of Feb 26, 2019
William End	May 11, 2018	31,786 shares, last reported balance as of May 10, 2018
Thomas Craig	May 1, 2017	24,471 shares, last reported balance as of Apr 28, 2017
Barry Johnson	Aug 16, 2016	3,560 shares, last reported balance as of Aug 15, 2016
Michael Williams	Aug 15, 2016	59,113 shares, last reported balance as of Aug 11, 2016
Johnny Powers	Dec 8, 2015	25,961 shares, last reported balance as of Dec 5, 2015
Robert Murray	May 8, 2015	182,540 shares, last reported balance as of May 6, 2015
Jeffrey Fiarman	Jun 3, 2014	1,302 shares, last reported balance as of Jun 1, 2014
Jeffery Chadbourne	May 20, 2013	72 shares, last reported balance as of May 10, 2013
Willard Blanche Jr.	May 20, 2013	3,396 shares, last reported balance as of May 10, 2013
Ali Naqui	May 13, 2013	35,026 shares, last reported balance as of May 9, 2013
Conan Deady	Mar 7, 2013	14,194 shares, last reported balance as of Mar 5, 2013
Merilee Raines	Feb 27, 2013	80,014 shares, last reported balance as of Feb 25, 2013
William Brown III	Feb 19, 2013	34,518 shares, last reported balance as of Feb 14, 2013
Daniel Meyaard	Feb 19, 2013	8,832 shares, last reported balance as of Feb 14, 2013
Joseph Vumbacco	Aug 13, 2012	7,120 shares, last reported balance as of Aug 9, 2012
William Goodspeed	Apr 28, 2011	9,240 shares, last reported balance as of Apr 26, 2011
Thomas Dupree	Feb 22, 2011	11,366 shares, last reported balance as of Feb 17, 2011
William Wallen	Feb 17, 2010	40,114 shares, last reported balance as of Feb 14, 2010
Errol Desouza	May 1, 2009	14,552 shares, last reported balance as of Apr 30, 2009
Sam Fratoni	Feb 2, 2009	102,312 shares, last reported balance as of Dec 10, 2008
Irene Kerr	Feb 19, 2008	1,820 shares, last reported balance as of Feb 14, 2008
Quentin Tonelli	May 24, 2007	99,832 shares, last reported balance as of May 23, 2007
Robert Hulsy	Mar 20, 2007	104,928 shares, last reported balance as of Mar 16, 2007
Laurel Labauve	Feb 16, 2006	No balance on record
Jennifer Joiner	Feb 16, 2006	No balance on record
Mary Good	May 3, 2005	2,488 shares, last reported balance as of Apr 29, 2005
James Moody Jr.	May 3, 2005	194,864 shares, last reported balance as of Apr 29, 2005
Louis Pollock	Jan 30, 2004	46,308 shares, last reported balance as of Jan 28, 2004
Erwin Workman Jr.		No balance on record

Idexx Laboratories insiders sold $37.7M in the past 12 months. How much of their stake is that?

What stands out

Who sold, and how much of their stake

Selling by month

Common questions

Is the Idexx Laboratories CEO selling stock?

Why are Idexx Laboratories insiders selling?

Are any Idexx Laboratories insiders buying?

How much of their stake did Idexx Laboratories insiders sell?

The evidence

No plan disclosed · $37.7M

Taxes

Sales by month