Thermo Fisher Scientific Inc.
MX ˙ BMV ˙ US8835561023
SecurityMX:TMO / Thermo Fisher Scientific Inc.
Institution1832 Asset Management L.P.
Latest Disclosed Ownership1,969,618 shares
Latest Disclosed Value $ 968,126,336
1832 Asset Management L.P. ownership in TMO / Thermo Fisher Scientific Inc.

On May 14, 2026 - 1832 Asset Management L.P. filed a 13F-HR form disclosing ownership of 1,969,618 shares of Thermo Fisher Scientific Inc. (MX:TMO) valued at $968,126,336 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 1,244,525 shares of Thermo Fisher Scientific Inc.. This represents a change in shares of 58.26% during the quarter.

1832 Asset Management L.P. has a history of taking positions in derivatives of the underlying security (TMO) in the form of stock options. The firm currently holds call 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.

MX:TMO / Thermo Fisher Scientific 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)
2026-05-14 2026-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 1,969,618 725,093 58.26 968,126 34.25 0.8900
2026-02-13 2025-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 1,244,525 4,211 0.34 721,140 19.87 0.5492
2025-11-14 2025-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 1,240,314 100,372 8.81 601,577 30.16 0.4748
2025-08-13 2025-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 1,139,942 351,167 44.52 462,201 17.76 0.3606
2025-05-14 2025-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 788,775 245,212 45.11 392,494 38.80 0.3567
2025-02-14 2024-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 543,563 32,751 6.41 282,778 -10.51 0.2404
2024-11-13 2024-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 510,812 -56,961 -10.03 315,973 0.64 0.2404
2024-08-13 2024-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 567,773 -345,497 -37.83 313,978 -40.85 0.2550
2024-05-14 2024-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 913,270 -581,432 -38.90 530,802 -33.10 0.3142
2024-02-13 2023-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 1,494,702 73,089 5.14 793,373 10.26 1.1426
2023-11-13 2023-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 1,421,613 168,048 13.41 719,578 10.02 1.0206
2023-08-14 2023-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 1,253,565 215 0.02 654,048 -9.46 1.2717
2023-05-12 2023-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 1,253,350 26,210 2.14 722,393 6.90 1.4858
2023-02-15 2022-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 1,227,140 189,187 18.23 675,774 28.37 1.3891
2022-11-14 2022-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 1,037,953 -4,675 -0.45 526,439 -7.06 1.1215
2022-08-15 2022-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 1,042,628 180,533 20.94 566,439 12.79 1.1414
2022-05-16 2022-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 862,095 165,450 23.75 502,213 7.43 0.8198
2022-02-15 2021-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 696,645 68,925 10.98 467,469 27.73 0.8272
2021-11-15 2021-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 627,720 -82,329 -11.59 365,975 1.75 0.6858
2021-08-20 2021-06-30 13F/A-1 THERMO FISHER SCIENTIFIC COM 883556102 710,049 -29,496 -3.99 359,680 7.31 0.6954
2021-08-16 2021-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 710,049 -29,496 359,680 0.6965
2021-05-17 2021-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 739,545 159,576 27.51 335,178 24.91 0.7244
2021-02-16 2020-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 579,969 -180,161 -23.70 268,340 -19.27 0.6276
2020-11-16 2020-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 760,130 184,380 32.02 332,372 63.33 0.8678
2020-08-14 2020-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 575,750 290,633 101.93 203,498 149.08 0.6108
2020-05-26 2020-03-31 13F/A-1 THERMO FISHER SCIENTIFIC COM 883556102 285,117 4,215 1.50 81,701 -10.92 0.2946
2020-05-14 2020-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 269,777 -11,125 77,299 584,460.5579
2020-02-14 2019-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 280,902 202,603 258.76 91,720 310.84 0.2792
2019-11-14 2019-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 78,299 -555,604 -87.65 22,325 -88.02 0.0711
2019-08-14 2019-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 633,903 -164,140 -20.57 186,387 -13.94 0.6028
2019-05-15 2019-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 798,043 25,413 3.29 216,586 25.27 0.7378
2019-02-14 2018-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 772,630 179,210 30.20 172,889 19.28 0.6836
2018-11-14 2018-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 593,420 155,620 35.55 144,949 59.89 0.4727
2018-08-14 2018-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 437,800 130,534 42.48 90,658 42.44 0.3070
2018-05-15 2018-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 307,266 225,203 274.43 63,645 310.14 0.2345
2018-02-14 2017-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 82,063 -444,549 -84.42 15,518 -83.94 0.0504
2017-11-14 2017-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 526,612 496,816 1,667.39 96,626 1,756.41 0.3385
2017-08-14 2017-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 29,796 -13,937 -31.87 5,205 -22.66 0.0236
2017-05-15 2017-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 43,733 -188,995 -81.21 6,730 -79.24 0.0241
2017-04-01 2016-12-31 13F/A-1 THERMO FISHER SCIENTIFIC COM 883556102 232,728 -467,351 -66.76 32,425 -70.88 0.0994
2017-02-14 2016-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 699,880 108,715
2016-11-15 2016-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 700,079 371,083 112.79 111,350 127.56 0.4183
2016-08-12 2016-06-30 13F/A-1 THERMO FISHER SCIENTIFIC COM 883556102 328,996 247,514 303.77 48,933 156.33 0.1903
2016-08-12 2016-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 328,996 247,514 81,467 0.1963
2016-05-12 2016-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 81,482 -340,267 -80.68 19,090 -68.39 0.0465
2016-02-12 2015-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 421,749 25,939 6.55 60,398 24.46 0.2610
2015-11-12 2015-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 395,810 -26,145 -6.20 48,527 -11.20 0.2030
2015-08-13 2015-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 421,955 -391,850 -48.15 54,650 -49.85 0.1854
2015-05-13 2015-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 813,805 -207,935 -20.35 108,973 -14.57 0.4099
2015-02-12 2014-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 1,021,740 88,987 9.54 127,564 12.52 0.3950
2014-11-12 2014-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 932,753 358,021 62.29 113,369 67.07 0.3700
2014-08-13 2014-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 574,732 -647,978 -53.00 67,858 -53.18 0.2138
2014-05-14 2014-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 1,222,710 132,910 12.20 144,931 19.41 0.4982
2014-02-13 2013-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 1,089,800 -216,960 -16.60 121,373 1.00 0.4668
2013-11-13 2013-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 1,306,760 -62,370 -4.56 120,174 3.78 0.5328
2013-08-14 2013-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 1,369,130 1,369,130 115,798 0.5071
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
(%)
2026-02-13 2025-12-31 13F THERMO FISHER SCIENTIFIC COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-11-14 2025-09-30 13F THERMO FISHER SCIENTIFIC COM Call 450,000 50.00 218,259 79.43 n/a n/a n/a
2025-08-13 2025-06-30 13F THERMO FISHER SCIENTIFIC COM Call 300,000 121,638 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.