IDEXX Laboratories (IDXX) insider buying and selling
Every Table I transaction reported by directors and officers of S&P 500 companies on SEC Form 4 filings (2 business days to file): each row labeled with its official transaction code, nothing filtered out beforehand.
Open-market purchases (code P) are the rare signal, in green; sales (code S) are common and often pre-scheduled (10b5-1). Table II (derivatives) is not included: its prices are exercise prices, not market values. Guide: insider buying.
| Date | Ticker | Insider | Role | Shares | Price | Amount | % of stake | Type / filing |
|---|
Download these transactions as CSV No account, no sign-up. The data is public: it comes from SEC Form 4 filings.
IDEXX Laboratories, Inc. (IDXX) insider buying and selling: no purchases, 9 sales
59 Form 4 Table I transactions filed with the SEC by IDEXX Laboratories, Inc. insiders between 2025-08-26 and 2026-09-09 (15-month history): 0 open-market purchases and 9 sales, plus 50 transactions under other Form 4 codes, broken down one by one below. The largest open-market trade is a sale of $15.3M by Mazelsky Jonathan Jay on 2026-02-26.
IDEXX Laboratories insider buying and selling over the last 12 months
Between Oct 21, 2025 and Oct 20, 2026, IDEXX Laboratories insiders filed 8 sales worth $37.7M on the open market, and no purchases.
The biggest seller was Mazelsky Jonathan Jay (President and CEO): $15.3M in 1 sale, out of 6 different sellers.
The largest trade of the period was a sale of $15.3M on Feb 26, 2026, by Mazelsky Jonathan Jay (President and CEO). Form 4 on sec.gov (0000874716-26-000043).
None of the 8 sales carries the 10b5-1 plan flag on the Form 4 (sales scheduled months ahead).
The last three months show 1 sale, against 0 in the three before. The latest sale from Sep 4, 2026.
Against its sector (Healthcare, 59 companies with an insider page on this site), over the same dates the median is 9 sales and 0 purchases on the open market. IDEXX Laboratories has more sales than 27 of the other 58, ranks 19 of 59 by net dollars sold, and 19 of the 59 have at least one purchase.
The 20 most important trades
With no open-market purchases, the table starts with IDXX's sales, largest first. The full history is in the tool above, already searched.
See all 59 IDXX trades in the full history →
| Trade date | Filed | Insider | Role | Amount | Code | Filing |
|---|---|---|---|---|---|---|
| 2026-02-26 | 2026-03-02 | Mazelsky Jonathan Jay | President and CEO | $15.3M | S — Open-market sale13 Form 4 footnotesF1 Represents the weighted average price of the shares sold ranging from a low of $650.00 to a high of $650.96 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F2 Represents the weighted average price of the shares sold ranging from a low of $651.06 to a high of $651.85 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F3 Represents the weighted average price of the shares sold ranging from a low of $652.105 to a high of $653.06 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F4 Represents the weighted average price of the shares sold ranging from a low of $653.19 to a high of $654.155 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F5 Represents the weighted average price of the shares sold ranging from a low of $654.24 to a high of $655.2175 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F6 Represents the weighted average price of the shares sold ranging from a low of $655.275 to a high of $656.205 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F7 Represents the weighted average price of the shares sold ranging from a low of $656.28 to a high of $657.27 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F8 Represents the weighted average price of the shares sold ranging from a low of $657.305 to a high of $658.275 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F9 Represents the weighted average price of the shares sold ranging from a low of $658.30 to a high of $659.24 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F10 Represents the weighted average price of the shares sold ranging from a low of $659.31 to a high of $660.275 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F11 Represents the weighted average price of the shares sold ranging from a low of $660.59 to a high of $661.55 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F12 Represents the weighted average price of the shares sold ranging from a low of $661.65 to a high of $662.55 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F13 Represents the weighted average price of the shares sold ranging from a low of $662.72 to a high of $663.505 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. | SEC |
| 2026-02-10 | 2026-02-11 | Fennell George | Executive Vice President | $7.3M | S — Open-market sale7 Form 4 footnotesF1 Represents the weighted average price of the shares sold ranging from a low of $642.595 to a high of $643.47 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F2 Represents the weighted average price of the shares sold ranging from a low of $643.65 to a high of $644.47 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F3 Represents the weighted average price of the shares sold ranging from a low of $644.75 to a high of $645.60 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F4 Represents the weighted average price of the shares sold ranging from a low of $645.80 to a high of $646.71 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F5 Represents the weighted average price of the shares sold ranging from a low of $646.825 to a high of $647.69 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F6 Represents the weighted average price of the shares sold ranging from a low of $648.02 to a high of $649.00 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F7 Represents the weighted average price of the shares sold ranging from a low of $649.05 to a high of $649.72 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. | SEC |
| 2025-11-07 | 2025-11-10 | Hunt Nimrata | Executive Vice President | $6.6M | S — Open-market sale4 Form 4 footnotesF2 Represents the weighted average price of the shares sold ranging from a low of $702.00 to a high of $703.00 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F3 Represents the weighted average price of the shares sold ranging from a low of $703.05 to a high of $703.97 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F4 Represents the weighted average price of the shares sold ranging from a low of $704.235 to a high of $705.175 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F5 Represents the weighted average price of the shares sold ranging from a low of $705.26 to a high of $705.92 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. | SEC |
| 2026-02-17 | 2026-02-19 | Erickson Michael G | Executive Vice President | $3.4M | S — Open-market sale5 Form 4 footnotesF1 Represents the weighted average price of the shares sold ranging from a low of $623.28 to a high of $624.27 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F2 Represents the weighted average price of the shares sold ranging from a low of $624.89 to a high of $625.56 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F3 Represents the weighted average price of the shares sold ranging from a low of $626.045 to a high of $628.38 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F4 Represents the weighted average price of the shares sold ranging from a low of $627.74 to a high of $628.67 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. F5 Represents the weighted average price of the shares sold ranging from a low of $628.755 to a high of $629.615 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. | SEC |
| 2026-02-26 | 2026-02-27 | Hunt Nimrata | Executive Vice President | $1.8M | S — Open-market saleForm 4 footnoteF1 Represents the weighted average price of the shares sold ranging from a low of $661.35 to a high of $661.8275 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. | SEC |
| 2025-08-22 | 2025-08-26 | Szostak M Anne | Director | $1.4M | S — Open-market saleForm 4 footnoteF1 Represents the weighted average price of the shares sold ranging from a low of $647.30 to a high of $647.45 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. | SEC |
| 2026-09-04 | 2026-09-09 | Kingsley Lawrence D | Director | $1.2M | S — Open-market saleForm 4 footnoteF1 Represents the weighted average price of the shares sold ranging from a low of $531.88 to a high of $532.14 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. | SEC |
| 2026-03-03 | 2026-03-05 | Hunt Nimrata | Executive Vice President | $1.1M | S — Open-market saleForm 4 footnoteF1 Represents the weighted average price of the shares sold ranging from a low of $634.5301 to a high of $634.8201 per share. The undersigned undertakes, upon request by the Commission staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares purchased at each separate price. | SEC |
| 2026-02-17 | 2026-02-19 | Vandebroek Sophie V. | Director | $920k | S — Open-market sale | SEC |
| 2025-11-07 | 2025-11-10 | Hunt Nimrata | Executive Vice President | $4.8M | M — Option exerciseForm 4 footnoteF1 Includes 11 shares purchased under the Issuer Employee Stock Purchase Plan on September 30, 2025. | SEC |
| 2026-02-26 | 2026-03-02 | Mazelsky Jonathan Jay | President and CEO | $3.3M | M — Option exercise | SEC |
| 2026-02-17 | 2026-02-19 | Erickson Michael G | Executive Vice President | $914k | M — Option exercise | SEC |
| 2026-02-10 | 2026-02-11 | Fennell George | Executive Vice President | $770k | M — Option exercise | SEC |
| 2026-02-14 | 2026-02-17 | Hunt Nimrata | Executive Vice President | $726k | F — Tax withholding (shares surrendered for taxes)Form 4 footnoteF2 Closing price of Issuer common stock on Nasdaq Global Select Market on February 13, 2026. | SEC |
| 2026-02-14 | 2026-02-17 | Erickson Michael G | Executive Vice President | $613k | F — Tax withholding (shares surrendered for taxes)2 Form 4 footnotesF3 Closing price of Issuer common stock on Nasdaq Global Select Market on February 13, 2026. F4 Includes 184 vested but deferred RSUs. | SEC |
| 2026-02-14 | 2026-02-17 | Mazelsky Jonathan Jay | President and CEO | $576k | F — Tax withholding (shares surrendered for taxes)Form 4 footnoteF2 Closing price of Issuer common stock on Nasdaq Global Select Market on February 13, 2026. | SEC |
| 2026-02-14 | 2026-02-17 | Schreck Michael | Executive Vice President | $551k | F — Tax withholding (shares surrendered for taxes)Form 4 footnoteF2 Closing price of Issuer common stock on Nasdaq Global Select Market on February 13, 2026. | SEC |
| 2026-02-19 | 2026-02-19 | Erickson Michael G | Executive Vice President | $547k | M — Option exerciseForm 4 footnoteF6 Includes 184 vested but deferred restricted stock units. | SEC |
| 2025-08-22 | 2025-08-26 | Szostak M Anne | Director | $452k | M — Option exercise | SEC |
| 2026-02-17 | 2026-02-19 | Vandebroek Sophie V. | Director | $316k | M — Option exercise | SEC |
The period balance: money in, money out
In the Form 4 filings submitted between Aug 26, 2025 and Sep 9, 2026 there is not one open-market purchase of IDEXX Laboratories, Inc.: 9 sales worth $39.1M and zero dollars bought.
Only codes P and S count, where an insider puts in or takes out their own money. A selling balance like IDEXX Laboratories, Inc.'s is the norm in the S&P 500, where much of the pay comes as stock. It is not a recommendation to buy or sell: it is what was filed.
Every transaction, code by code
| Code | What it means | Trades | Reported amount |
|---|---|---|---|
| M | Option exercise | 30 | $11.7M |
| F | Tax withholding (shares surrendered for taxes) | 13 | $3.4M |
| S | Open-market sale | 9 | $39.1M |
| A | Grant or award | 4 | $100k |
| G | Gift | 3 | $0 |
| Total | Everything filed in the period | 59 | $54.3M |
22 of the 59 rows carry no usable amount on the Form 4: they count as trades and add $0. The code labels come from the SEC index.
Who has traded
Over the 15 months of history, 16 distinct people or entities have filed IDEXX Laboratories, Inc. transactions: none bought on the open market and 7 sold. Counted by CIK, the fixed number the SEC gives each filer, and not by name, which each filer types their own way.
Of the 7 who sold on the open market (9 sales in all), the three biggest sellers account for $32.2M of the $39.1M: 82% of the money in three people.
| Filer | Role | Transactions | Bought (count) | Sold (count) | Last filed |
|---|---|---|---|---|---|
| Mazelsky Jonathan Jay | President and CEO | 6 | — | $15.3M (1) | 2026-03-02 |
| Hunt Nimrata | Executive Vice President | 6 | — | $9.5M (3) | 2026-03-05 |
| Fennell George | Executive Vice President | 7 | — | $7.3M (1) | 2026-06-02 |
| Erickson Michael G | Executive Vice President | 5 | — | $3.4M (1) | 2026-02-19 |
| Szostak M Anne | Director | 5 | — | $1.4M (1) | 2026-05-11 |
| Kingsley Lawrence D | Director | 3 | — | $1.2M (1) | 2026-09-09 |
| Vandebroek Sophie V. | Director | 3 | — | $920k (1) | 2026-05-11 |
| Hooley Joseph L | Director | 5 | — | — | 2026-08-03 |
Shown here are the 8 who moved the most money, out of 16. The rest are in the full history, one link above. The name links to all their trades, in any company. "Transactions" counts any code; the money, open market only. Role: from their latest filing.
Month by month
By the month the trade was executed, not the month it was filed; months with no trades show zero. The busiest month was Feb 2026: 0 purchases and 5 sales, worth $28.7M. 10 of the 15 months have none.
| Month | Purchases | Amount | Sales | Amount |
|---|---|---|---|---|
| Aug 2025 | 0 | $0 | 1 | $1.4M |
| Sep 2025 | 0 | $0 | 0 | $0 |
| Oct 2025 | 0 | $0 | 0 | $0 |
| Nov 2025 | 0 | $0 | 1 | $6.6M |
| Dec 2025 | 0 | $0 | 0 | $0 |
| Jan 2026 | 0 | $0 | 0 | $0 |
| Feb 2026 | 0 | $0 | 5 | $28.7M |
| Mar 2026 | 0 | $0 | 1 | $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 | 0 | $0 | 1 | $1.2M |
| Oct 2026 | 0 | $0 | 0 | $0 |
The last month may be partial: a Form 4 is filed up to two business days later. The table does not say whether the pattern is good or bad; it says when it happened.
IDEXX Laboratories, Inc. (IDXX) analysis page →
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How to read this data
None of the 9 sales in the table is flagged as scheduled (10b5-1 plan), the kind signed months ahead and executed automatically. IDEXX Laboratories has no open-market purchase (code P) in the history, the most common case in the S&P 500: insiders are already paid in stock. The latest filing is from Sep 9, 2026, and a Form 4 arrives up to two business days after the trade.
14 of the 20 rows in the table carry footnotes from the Form 4 itself, folded into the code column and copied verbatim; a row with no footnote means the filing has none.
Guide: Insider buying · all guides
What is behind these trades
The concepts on this page, explained from scratch in the Academy. Free, no account.
- What the efficiency hypothesis says and what it does NOT sayIf an insider's purchase is public and anyone can read it, is there any information left in it? That is the exact question that brings people here.
- Who really moves the market: the types of investorWho sits on the other side of each order, and where a company's own insiders fit among them.
- Supply, demand and price: why it rises and falls constantlyHow a piece of news ends up inside the price, and why the reaction to a filed sale is rarely the one you would expect.
Source: SEC EDGAR Form 4. This is a list of public facts, not financial advice or a recommendation to buy or sell.