WESTFIELD CAPITAL MANAGEMENT CO LP
Position in IDXX — Idexx Laboratories Inc /De
CIK 1177719
BOSTON, MA
Position in IDXX
as of Mar 31, 2026
· filed May 11, 2026
Position Value
$74,652,705
-$25,099,613 QoQ
Shares Held
132,860
-9.9% QoQ
Ownership
0.168%
of shares outstanding
% of Portfolio
0.31%
of 13F equity value
Holder Rank
—
not a current holder
Holding Since
Mar 2020
21 quarters on record
Voting authority
Sole 80.97019418937226.ToString("F0")%
Shared 0.ToString("F0")%
None 19.029805810627728.ToString("F0")%
Common Shares in IDXX Over Time
Shares Held
Position Value (USD)
Position in Diagnostics & Research
Healthcare · as of Mar 31, 2026WESTFIELD CAPITAL MANAGEMENT CO LP holds $572,134,101 across 8 Diagnostics & Research names. IDXX ranks #5 (13.0% of the industry book) .
| # | Ticker | Company | Shares | Value (USD) | Open |
|---|---|---|---|---|---|
| 1 | NTRA |
Natera, Inc.
|
754,729 | $150,938,252 | |
| 2 | GH |
Guardant Health, Inc.
|
1,362,539 | $125,857,727 | |
| 3 | WGS |
GeneDx Holdings Corp.
|
1,369,108 | $87,924,115 | |
| 4 | ADPT |
Adaptive Biotechnologies Corp
|
5,436,718 | $75,461,645 | |
| 5 | IDXX |
Idexx Laboratories Inc /De
This page
|
132,860 | $74,652,705 | |
| 6 | RDNT |
RadNet, Inc.
|
531,893 | $29,727,499 | |
| 7 | DHR |
Danaher Corp /De/
|
110,492 | $20,949,283 | |
| 8 | TMO |
Thermo Fisher Scientific Inc.
|
13,474 | $6,622,875 |
All Filings in IDXX
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21 filing rows on record
| Report Date | Value (USD) | Shares | Type | Discretion | Filed | |
|---|---|---|---|---|---|---|
| 2026-03-31 | $74,652,705 | 132,860 | Shares | Sole | 2026-05-11 | |
| 2025-12-31 | $99,752,318 | 147,447 | Shares | Sole | 2026-02-11 | |
| 2025-09-30 | $60,138,076 | 94,129 | Shares | Sole | 2025-11-12 | |
| 2024-06-30 | $54,859,694 | 112,602 | Shares | Sole | 2024-08-14 | |
| 2024-03-31 | $92,879,298 | 172,021 | Shares | Sole | 2024-05-10 | |
| 2023-12-31 | $89,420,775 | 161,104 | Shares | Sole | 2024-02-09 | |
| 2023-09-30 | $63,671,759 | 145,612 | Shares | Sole | 2023-11-13 | |
| 2023-06-30 | $65,329,576 | 130,079 | Shares | Sole | 2023-08-11 | |
| 2023-03-31 | $66,472,133 | 132,923 | Shares | Sole | 2023-05-12 | |
| 2022-12-31 | $90,237,488 | 221,192 | Shares | Sole | 2023-02-13 | |
| 2022-09-30 | $69,553,087 | 213,484 | Shares | Sole | 2022-11-14 | |
| 2022-06-30 | $73,921,608 | 210,765 | Shares | Sole | 2022-08-12 | |
| 2022-03-31 | $112,334,394 | 205,342 | Shares | Sole | 2022-05-16 | |
| 2021-12-31 | $84,766,189 | 128,734 | Shares | Sole | 2022-02-10 | |
| 2021-09-30 | $46,702,202 | 75,096 | Shares | Sole | 2021-11-12 | |
| 2021-06-30 | $89,412,322 | 141,576 | Shares | Sole | 2021-08-10 | |
| 2021-03-31 | $102,879,384 | 210,254 | Shares | Sole | 2021-05-14 | |
| 2020-12-31 | $119,690,872 | 239,444 | Shares | Sole | 2021-02-12 | |
| 2020-09-30 | $107,917,343 | 274,522 | Shares | Sole | 2020-11-13 | |
| 2020-06-30 | $109,175,988 | 330,676 | Shares | Sole | 2020-08-13 | |
| 2020-03-31 | $85,984,783 | 354,957 | Shares | Sole | 2020-05-14 | |
| No filing history on record for this holder in this stock. | ||||||