IDEXX Laboratories, Inc.
US ˙ NasdaqGS ˙ US45168D1046

SecurityIDXX / IDEXX Laboratories, Inc.
InstitutionCitigroup Inc
Latest Disclosed Ownership120,283 shares
Latest Disclosed Value $ 67,585,815
Citigroup Inc ownership in IDXX / IDEXX Laboratories, Inc.

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 120,283 shares of IDEXX Laboratories, Inc. (US:IDXX) valued at $67,585,815 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 117,007 shares of IDEXX Laboratories, Inc.. This represents a change in shares of 2.80% during the quarter. The current value of the position is $67,446,287 USD.

Citigroup Inc has a history of taking positions in derivatives of the underlying security (IDXX) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD and put options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

IDXX / IDEXX Laboratories, Inc. Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-11 2026-03-31 13F IDEXX LABS COM 45168D104 120,283 3,276 2.80 67,586 -14.62 0.0288
2026-02-13 2025-12-31 13F IDEXX LABS COM 45168D104 117,007 -27,445 -19.00 79,159 -14.23 0.0349
2025-11-10 2025-09-30 13F IDEXX LABS COM 45168D104 144,452 7,670 5.61 92,289 25.80 0.0411
2025-08-11 2025-06-30 13F IDEXX LABS COM 45168D104 136,782 4,546 3.44 73,362 32.11 0.0360
2025-05-12 2025-03-31 13F IDEXX LABS COM 45168D104 132,236 30,122 29.50 55,533 31.54 0.0284
2025-02-12 2024-12-31 13F IDEXX LABS COM 45168D104 102,114 -31,165 -23.38 42,218 -37.30 0.0250
2024-11-12 2024-09-30 13F IDEXX LABS COM 45168D104 133,279 -7,998 -5.66 67,335 -2.17 0.0390
2024-08-12 2024-06-30 13F IDEXX LABS COM 45168D104 141,277 42,705 43.32 68,830 29.33 0.0441
2024-05-10 2024-03-31 13F IDEXX LABS COM 45168D104 98,572 1,090 1.12 53,222 -1.64 0.0350
2024-02-09 2023-12-31 13F IDEXX LABS COM 45168D104 97,482 6,096 6.67 54,107 35.40 0.0381
2023-12-06 2023-09-30 13F/A-1 IDEXX LABS COM 45168D104 91,386 4,582 5.28 39,960 -8.34 0.0299
2023-11-09 2023-09-30 13F IDEXX LABS COM 45168D104 91,386 4,582 39,960 0.0298
2023-08-10 2023-06-30 13F IDEXX LABS COM 45168D104 86,804 24,622 39.60 43,595 40.20 0.0286
2023-05-11 2023-03-31 13F IDEXX LABS COM 45168D104 62,182 -3,830 -5.80 31,096 15.47 0.0218
2023-02-09 2022-12-31 13F IDEXX LABS COM 45168D104 66,012 5,247 8.63 26,930 36.03 0.0214
2022-11-10 2022-09-30 13F IDEXX LABS COM 45168D104 60,765 3,045 5.28 19,797 -2.20 0.0142
2022-08-10 2022-06-30 13F IDEXX LABS COM 45168D104 57,720 -36,512 -38.75 20,243 -60.73 0.0151
2022-05-12 2022-03-31 13F IDEXX LABS COM 45168D104 94,232 -14,085 -13.00 51,550 -27.72 0.0313
2022-02-10 2021-12-31 13F IDEXX LABS COM 45168D104 108,317 19,364 21.77 71,322 28.93 0.0382
2021-11-10 2021-09-30 13F IDEXX LABS COM 45168D104 88,953 10,973 14.07 55,319 12.33 0.0327
2021-08-10 2021-06-30 13F IDEXX LABS COM 45168D104 77,980 -11,672 -13.02 49,247 12.26 0.0296
2021-05-13 2021-03-31 13F IDEXX LABS COM 45168D104 89,652 -38,570 -30.08 43,868 -31.56 0.0284
2021-02-11 2020-12-31 13F IDEXX LABS COM 45168D104 128,222 44,880 53.85 64,094 95.64 0.0378
2020-11-12 2020-09-30 13F IDEXX LABS COM 45168D104 83,342 4,364 5.53 32,762 25.65 0.0214
2020-08-12 2020-06-30 13F IDEXX LABS COM 45168D104 78,978 23,128 41.41 26,075 92.72 0.0204
2020-05-12 2020-03-31 13F IDEXX LABS COM 45168D104 55,850 -10,666 -16.04 13,530 -22.11 0.0122
2020-02-12 2019-12-31 13F IDEXX LABS COM 45168D104 66,516 -42,926 -39.22 17,371 -41.63 0.0126
2019-11-08 2019-09-30 13F IDEXX LABS COM 45168D104 109,442 6,195 6.00 29,761 4.70 0.0236
2019-08-12 2019-06-30 13F IDEXX LABS COM 45168D104 103,247 14,875 16.83 28,426 43.86 0.0230
2019-05-13 2019-03-31 13F IDEXX LABS COM 45168D104 88,372 13,069 17.36 19,760 41.06 0.0190
2019-02-12 2018-12-31 13F IDEXX LABS COM 45168D104 75,303 46,926 165.37 14,008 97.74 0.0142
2018-11-13 2018-09-30 13F IDEXX LABS COM 45168D104 28,377 9,764 52.46 7,084 74.61 0.0063
2018-08-10 2018-06-30 13F IDEXX LABS COM 45168D104 18,613 -13,213 -41.52 4,057 -33.39 0.0037
2018-05-11 2018-03-31 13F IDEXX LABS COM 45168D104 31,826 19,569 159.66 6,091 217.74 0.0050
2018-02-12 2017-12-31 13F IDEXX LABS COM 45168D104 12,257 -19,252 -61.10 1,917 -60.86 0.0015
2017-11-13 2017-09-30 13F IDEXX LABS COM 45168D104 31,509 3,698 13.30 4,898 9.09 0.0040
2017-08-11 2017-06-30 13F IDEXX LABS COM 45168D104 27,811 237 0.86 4,490 5.30 0.0040
2017-05-12 2017-03-31 13F IDEXX LABS COM 45168D104 27,574 610 2.26 4,264 34.81 0.0038
2017-02-10 2016-12-31 13F IDEXX LABS COM 45168D104 26,964 -17,779 -39.74 3,163 -37.28 0.0029
2016-11-10 2016-09-30 13F IDEXX LABS COM 45168D104 44,743 35,811 400.93 5,043 507.59 0.0047
2016-08-12 2016-06-30 13F IDEXX LABS COM 45168D104 8,932 752 9.19 830 29.49 0.0008
2016-05-13 2016-03-31 13F IDEXX LABS COM 45168D104 8,180 402 5.17 641 13.05 0.0007
2016-02-12 2015-12-31 13F IDEXX LABS COM 45168D104 7,778 182 2.40 567 0.71 0.0006
2015-11-13 2015-09-30 13F IDEXX LABS COM 45168D104 7,596 -9,628 -55.90 563 -49.05 0.0005
2015-08-13 2015-06-30 13F IDEXX LABS COM 45168D104 17,224 8,245 91.83 1,105 -20.39 0.0010
2015-05-14 2015-03-31 13F IDEXX LABS COM 45168D104 8,979 -13,026 -59.20 1,388 -57.45 0.0013
2015-02-17 2014-12-31 13F IDEXX LABS COM 45168D104 22,005 18,959 622.42 3,262 811.17 0.0029
2014-11-14 2014-09-30 13F IDEXX LABS COM 45168D104 3,046 -224 -6.85 358 -17.89 0.0003
2014-08-14 2014-06-30 13F IDEXX LABS COM 45168D104 3,270 112 3.55 436 13.84 0.0004
2014-05-15 2014-03-31 13F IDEXX LABS COM 45168D104 3,158 33 1.06 383 15.02 0.0004
2014-02-14 2013-12-31 13F IDEXX LABS COM 45168D104 3,125 -15,388 -83.12 333 -81.94 0.0003
2013-11-14 2013-09-30 13F IDEXX LABS COM 45168D104 18,513 -984 -5.05 1,844 5.37 0.0017
2013-08-14 2013-06-30 13F IDEXX LABS COM 45168D104 19,497 19,497 1,750 0.0017
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2021-02-11 2020-12-31 13F IDEXX LABS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-11-12 2020-09-30 13F IDEXX LABS COM Call 1,100 -59.26 432 -51.52 n/a n/a n/a
2020-08-12 2020-06-30 13F IDEXX LABS COM Call 2,700 0.00 891 36.24 n/a n/a n/a
2020-05-12 2020-03-31 13F IDEXX LABS COM Call 2,700 -32.50 654 -37.42 n/a n/a n/a
2020-02-12 2019-12-31 13F IDEXX LABS COM Call 4,000 -48.05 1,045 -50.10 n/a n/a n/a
2019-11-08 2019-09-30 13F IDEXX LABS COM Call 7,700 63.83 2,094 61.82 n/a n/a n/a
2019-08-12 2019-06-30 13F IDEXX LABS COM Call 4,700 56.67 1,294 92.85 n/a n/a n/a
2019-05-13 2019-03-31 13F IDEXX LABS COM Call 3,000 -44.44 671 -33.23 n/a n/a n/a
2019-02-12 2018-12-31 13F IDEXX LABS COM Call 5,400 134.78 1,005 75.09 n/a n/a n/a
2018-11-13 2018-09-30 13F IDEXX LABS COM Call 2,300 -48.89 574 -41.49 n/a n/a n/a
2018-08-10 2018-06-30 13F IDEXX LABS COM Call 4,500 125.00 981 156.14 n/a n/a n/a
2018-05-11 2018-03-31 13F IDEXX LABS COM Call 2,000 -64.29 383 -56.28 n/a n/a n/a
2018-02-12 2017-12-31 13F IDEXX LABS COM Call 5,600 133.33 876 134.85 n/a n/a n/a
2017-11-13 2017-09-30 13F IDEXX LABS COM Call 2,400 100.00 373 92.27 n/a n/a n/a
2017-08-11 2017-06-30 13F IDEXX LABS COM Call 1,200 -29.41 194 -26.24 n/a n/a n/a
2017-05-12 2017-03-31 13F IDEXX LABS COM Call 1,700 -85.34 263 -80.66 n/a n/a n/a
2017-02-10 2016-12-31 13F IDEXX LABS COM Call 11,600 2,220.00 1,360 2,328.57 n/a n/a n/a
2016-11-10 2016-09-30 13F IDEXX LABS COM Call 500 56 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2020-11-12 2020-09-30 13F IDEXX LABS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-08-12 2020-06-30 13F IDEXX LABS COM Put 500 -37.50 165 -14.95 n/a n/a n/a
2020-05-12 2020-03-31 13F IDEXX LABS COM Put 800 -73.33 194 -75.26 n/a n/a n/a
2020-02-12 2019-12-31 13F IDEXX LABS COM Put 3,000 -41.18 784 -43.48 n/a n/a n/a
2019-11-08 2019-09-30 13F IDEXX LABS COM Put 5,100 -22.73 1,387 -23.67 n/a n/a n/a
2019-08-12 2019-06-30 13F IDEXX LABS COM Put 6,600 94.12 1,817 139.08 n/a n/a n/a
2019-05-13 2019-03-31 13F IDEXX LABS COM Put 3,400 126.67 760 172.40 n/a n/a n/a
2019-02-12 2018-12-31 13F IDEXX LABS COM Put 1,500 -66.67 279 -75.16 n/a n/a n/a
2018-11-13 2018-09-30 13F IDEXX LABS COM Put 4,500 -38.36 1,123 -29.42 n/a n/a n/a
2018-08-10 2018-06-30 13F IDEXX LABS COM Put 7,300 46.00 1,591 66.25 n/a n/a n/a
2018-05-11 2018-03-31 13F IDEXX LABS COM Put 5,000 2.04 957 24.93 n/a n/a n/a
2018-02-12 2017-12-31 13F IDEXX LABS COM Put 4,900 444.44 766 447.14 n/a n/a n/a
2017-11-13 2017-09-30 13F IDEXX LABS COM Put 900 -10.00 140 -13.04 n/a n/a n/a
2017-08-11 2017-06-30 13F IDEXX LABS COM Put 1,000 -68.75 161 -67.47 n/a n/a n/a
2017-05-12 2017-03-31 13F IDEXX LABS COM Put 3,200 -5.88 495 24.06 n/a n/a n/a
2017-02-10 2016-12-31 13F IDEXX LABS COM Put 3,400 399 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.