Thermo Fisher Scientific Inc.
MX ˙ BMV ˙ US8835561023
SecurityMX:TMO / Thermo Fisher Scientific Inc.
InstitutionWelch & Forbes Llc
Latest Disclosed Ownership88,934 shares
Latest Disclosed Value $ 43,713,828
Welch & Forbes Llc reports 0.17% decrease in ownership of TMO / Thermo Fisher Scientific Inc.

On May 1, 2026 - Welch & Forbes Llc filed a 13F-HR form disclosing ownership of 88,934 shares of Thermo Fisher Scientific Inc. (MX:TMO) valued at $43,713,828 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 89,084 shares of Thermo Fisher Scientific Inc.. This represents a change in shares of -0.17% during the quarter.

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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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)
2026-05-01 2026-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 88,934 -150 -0.17 43,714 -15.32 0.5652
2026-02-10 2025-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 89,084 -642 -0.72 51,620 18.62 0.6254
2025-11-04 2025-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 89,726 -1,388 -1.52 43,519 17.80 0.5241
2025-08-05 2025-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 91,114 -655 -0.71 36,943 -19.10 0.4613
2025-05-02 2025-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 91,769 738 0.81 45,664 -3.57 0.5974
2025-02-07 2024-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 91,031 -3,246 -3.44 47,357 -18.79 0.6089
2024-11-04 2024-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 94,277 384 0.41 58,317 14.97 0.7422
2024-08-02 2024-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 93,893 25 0.03 50,722 -7.03 0.6769
2024-05-03 2024-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 93,868 6,231 7.11 54,557 17.28 0.7489
2024-02-06 2023-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 87,637 66 0.08 46,517 4.94 0.7026
2023-11-03 2023-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 87,571 3,586 4.27 44,326 1.15 0.7329
2023-07-28 2023-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 83,985 1,642 1.99 43,819 -7.67 0.6912
2023-04-14 2023-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 82,343 1,274 1.57 47,460 6.31 0.8037
2023-02-02 2022-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 81,069 -307 -0.38 44,644 8.16 0.8002
2022-10-31 2022-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 81,376 758 0.94 41,274 -5.76 0.8060
2022-07-22 2022-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 80,618 2,099 2.67 43,797 -5.56 0.8013
2022-04-25 2022-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 78,519 2,392 3.14 46,377 -8.70 0.7306
2022-01-19 2021-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 76,127 302 0.40 50,795 17.25 0.7604
2021-10-13 2021-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 75,825 2,684 3.67 43,322 17.41 0.7200
2021-07-22 2021-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 73,141 3,210 4.59 36,898 15.61 0.6234
2021-04-14 2021-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 69,931 2,008 2.96 31,916 0.88 0.5894
2021-01-20 2020-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 67,923 482 0.71 31,638 6.25 0.6189
2020-10-23 2020-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 67,441 1,347 2.04 29,776 24.33 0.6426
2020-07-15 2020-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 66,094 3,294 5.25 23,949 34.47 0.5610
2020-04-17 2020-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 62,800 2,676 4.45 17,810 -8.82 0.4974
2020-01-17 2019-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 60,124 725 1.22 19,533 12.90 0.4346
2019-10-11 2019-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 59,399 1,755 3.04 17,301 2.20 0.4129
2019-07-12 2019-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 57,644 2,371 4.29 16,929 11.90 0.4121
2019-04-29 2019-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 55,273 1,990 3.73 15,129 26.88 0.3795
2019-02-05 2018-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 53,283 1,855 3.61 11,924 -5.01 0.3362
2018-10-17 2018-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 51,428 3,473 7.24 12,553 26.38 0.2992
2018-07-16 2018-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 47,955 35,913 298.23 9,933 299.56 0.2568
2018-04-12 2018-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 12,042 -11 -0.09 2,486 8.65 0.0641
2018-01-26 2017-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 12,053 -95 -0.78 2,288 -0.44 0.0611
2017-11-13 2017-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 12,148 0 0.00 2,298 8.40 0.0605
2017-07-31 2017-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 12,148 34 0.28 2,120 13.92 0.0592
2017-07-31 2017-03-31 13F/A-1 THERMO FISHER SCIENTIFIC COM 883556102 12,114 -334 -2.68 1,861 5.98 0.0533
2017-04-27 2017-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 12,114 1,861
2017-02-07 2016-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 12,448 1,310 11.76 1,756 -0.90 0.0525
2016-11-02 2016-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 11,138 -265 -2.32 1,772 5.16 0.0613
2016-08-02 2016-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 11,403 -200 -1.72 1,685 2.56 0.0513
2016-05-05 2016-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 11,603 262 2.31 1,643 2.11 0.0512
2016-01-27 2015-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 11,341 -1,221 -9.72 1,609 4.75 0.0516
2015-11-05 2015-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 12,562 -423 -3.26 1,536 -8.84 0.0513
2015-08-11 2015-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 12,985 3,350 34.77 1,685 30.22 0.0524
2015-04-30 2015-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 9,635 9,635 0.00 1,294 0.0389
2015-01-27 2014-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 0 -10,066 -100.00 0 -100.00
2014-10-27 2014-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 10,066 -1,440 -12.52 1,225 -9.79 0.0374
2014-07-31 2014-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 11,506 840 7.88 1,358 5.85 0.0429
2014-05-01 2014-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 10,666 1,950 22.37 1,283 32.27 0.0406
2014-01-17 2013-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 8,716 150 1.75 970 22.78 0.0307
2013-10-31 2013-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 8,566 1,176 15.91 790 26.40 0.0266
2013-08-08 2013-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 7,390 7,390 625 0.0223
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.