Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in IDXX held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 8.4M | $4.70B | -2.0% | 10.533% | 0.08% |
| 2 | VANGUARD CAPITAL MANAGEMENT LLC | 5.2M | $2.91B | — | 6.525% | 0.07% |
| 3 | VANGUARD PORTFOLIO MANAGEMENT LLC | 3.9M | $2.20B | — | 4.924% | 0.12% |
| 4 | STATE STREET CORP | 3.7M | $2.06B | +0.5% | 4.626% | 0.07% |
| 5 | GEODE CAPITAL MANAGEMENT, LLC | 2.7M | $1.50B | +3.0% | 3.350% | 0.09% |
| 6 | Invesco Ltd. | 1.7M | $943.2M | +11.7% | 2.113% | 0.14% |
| 7 | BAMCO INC /NY/ | 1.6M | $917.8M | -9.2% | 2.056% | 2.77% |
| 8 | Bank of New York Mellon Corp | 1.5M | $845.4M | -7.4% | 1.894% | 0.16% |
| 9 | Fundsmith LLP | 1.5M | $823.6M | -21.9% | 1.845% | 6.42% |
| 10 | MORGAN STANLEY | 1.3M | $739.4M | -15.3% | 1.657% | 0.04% |
| 11 | BLAIR WILLIAM & CO/IL | 946K | $531.7M | -5.5% | 1.192% | 1.52% |
| 12 | NORTHERN TRUST CORP | 912K | $512.4M | -1.2% | 1.148% | 0.07% |
| 13 | PRINCIPAL FINANCIAL GROUP INC | 881K | $495.2M | -9.1% | 1.110% | 0.26% |
| 14 | UBS ASSET MANAGEMENT AMERICAS INC | 872K | $489.8M | +1.4% | 1.098% | 0.10% |
| 15 | ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | 839K | $471.3M | +52.4% | 1.056% | 0.26% |
| 16 | Capital Research Global Investors | 781K | $439.0M | +28.6% | 0.984% | 0.07% |
| 17 | WELLINGTON MANAGEMENT GROUP LLP | 735K | $413.3M | -5.6% | 0.926% | 0.08% |
| 18 | GOLDMAN SACHS GROUP INC | 717K | $402.8M | -13.8% | 0.903% | 0.05% |
| 19 | POLEN CAPITAL MANAGEMENT LLC | 696K | $391.0M | -27.6% | 0.876% | 2.70% |
| 20 | FRANKLIN RESOURCES INC | 663K | $372.3M | +5.7% | 0.834% | 0.09% |
| 21 | Legal & General Group Plc | 651K | $365.7M | -2.9% | 0.819% | 0.08% |
| 22 | Amundi | 611K | $343.2M | -1.3% | 0.769% | 0.09% |
| 23 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 610K | $342.9M | +3.4% | 0.768% | 0.05% |
| 24 | AMERICAN CENTURY COMPANIES INC | 600K | $337.1M | -4.6% | 0.755% | 0.17% |
| 25 | DIMENSIONAL FUND ADVISORS LP | 573K | $322.1M | +4.3% | 0.722% | 0.07% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in IDXX — a direct measure of their conviction.
Filings activity in IDXX during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 1,279 | 4.9% | 85.82% | 19.01 pp | $38.23B | 18% |
| Q4 2025 | 1,345 | +7.4% | 104.83% | +5.29 pp | $46.70B | +5.3% |
| Q3 2025 | 1,252 | +4.2% | 99.54% | +14.03 pp | $44.34B | +16% |
| Q2 2025 | 1,201 | +9.8% | 85.51% | +19.98 pp | $38.09B | +30% |
| Q1 2025 | 1,094 | +1.4% | 65.53% | 1.81 pp | $29.19B | 2.7% |
| Q4 2024 | 1,079 | +0.9% | 67.34% | 9.78 pp | $30.00B | 13% |
| Q3 2024 | 1,069 | +0.5% | 77.12% | 2.05 pp | $34.35B | 2.6% |
| Q2 2024 | 1,064 | — | 79.17% | — | $35.27B | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying IDXX stock.
Based on Q1 2026 13F filings, institutional ownership of IDEXX Laboratories, Inc. stands at 85.8%, held across 1,279 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of IDXX, with approximately 8,365,553 shares worth $4.70B as of Q1 2026.
No marquee "smart money" managers (Berkshire, Burry, ARK, Tiger Global, Pershing Square, Baupost, etc.) currently appear among the top 25 institutional holders of IDXX.
Our composite Smart Money Score for IDXX is 16 out of 100 (Heavy Distribution). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
137 institutions opened new positions in IDXX during Q1 2026, while 203 fully exited. 151 added to existing positions and 988 trimmed.
IDXX institutional ownership fell by 19.01 percentage points quarter-over-quarter, with a net change of -66 holders.
The top 10 institutions account for 46.1% of all reported 13F value in IDXX, and the top 25 account for 62.4%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
IDEXX Laboratories, Inc. (IDXX) Institutional Ownership