Thermo Fisher Scientific Inc.
US ˙ NYSE ˙ US8835561023

SecurityTMO / Thermo Fisher Scientific Inc.
InstitutionWalleye Capital LLC
Latest Disclosed Ownership43,039 shares
Latest Disclosed Value $ 21,154,960
Walleye Capital LLC ownership in TMO / Thermo Fisher Scientific Inc.

On May 13, 2026 - Walleye Capital LLC filed a 13F-HR/A form disclosing ownership of 43,039 shares of Thermo Fisher Scientific Inc. (US:TMO) valued at $21,154,960 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 14,246 shares of Thermo Fisher Scientific Inc.. This represents a change in shares of 202.11% during the quarter. The current value of the position is $20,398,334 USD.

Walleye Capital LLC 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 3,800 of underlying shares valued at $1,867,814 USD and put options representing 2,200 of underlying shares valued at $1,081,366 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.

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)
2026-05-13 2026-03-31 13F/A-1 THERMO FISHER SCIENTIFIC COM 883556102 43,039 28,793 202.11 21,155 156.29 0.0880
2026-05-08 2026-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 43,039 28,793 21,155 0.0879
2026-02-13 2025-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 14,246 9,184 181.43 8,255 236.21 0.0253
2025-11-14 2025-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 5,062 2,671 111.71 2,455 153.35 0.0092
2025-08-13 2025-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 2,391 -21,704 -90.08 969 -91.92 0.0038
2025-05-14 2025-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 24,095 -28,341 -54.05 11,990 -56.05 0.0541
2025-02-13 2024-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 52,436 5,938 12.77 27,279 -5.16 0.0667
2024-11-14 2024-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 46,498 16,241 53.68 28,762 71.90 0.0598
2024-08-14 2024-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 30,257 4,188 16.07 16,732 10.43 0.0298
2024-05-15 2024-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 26,069 -25,833 -49.77 15,152 -45.00 0.0270
2024-02-14 2023-12-31 13F THERMO FISHER SCIENTIFIC COM 883556102 51,902 3,958 8.26 27,549 13.52 0.0584
2023-11-21 2023-09-30 13F/A-1 THERMO FISHER SCIENTIFIC COM 883556102 47,944 47,944 24,268 0.0621
2023-11-14 2023-09-30 13F THERMO FISHER SCIENTIFIC COM 883556102 47,944 47,944 24,268 0.0624
2023-08-14 2023-06-30 13F THERMO FISHER SCIENTIFIC COM 883556102 0 -300 -100.00 0 -100.00
2023-05-15 2023-03-31 13F THERMO FISHER SCIENTIFIC COM 883556102 300 300 173 0.0026
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
(%)
2026-05-13 2026-03-31 13F/A THERMO FISHER SCIENTIFIC COM Call 3,800 -80.00 1,868 -83.04 n/a n/a n/a
2026-05-08 2026-03-31 13F THERMO FISHER SCIENTIFIC COM Call 3,800 1,868 n/a n/a n/a
2026-02-13 2025-12-31 13F THERMO FISHER SCIENTIFIC COM Call 19,000 42.86 11,010 70.68 n/a n/a n/a
2025-11-14 2025-09-30 13F THERMO FISHER SCIENTIFIC COM Call 13,300 -63.36 6,451 -56.18 n/a n/a n/a
2025-08-13 2025-06-30 13F THERMO FISHER SCIENTIFIC COM Call 36,300 485.48 14,718 377.08 n/a n/a n/a
2025-05-14 2025-03-31 13F THERMO FISHER SCIENTIFIC COM Call 6,200 -61.73 3,085 -63.39 n/a n/a n/a
2025-02-13 2024-12-31 13F THERMO FISHER SCIENTIFIC COM Call 16,200 -19.40 8,428 -32.22 n/a n/a n/a
2024-11-14 2024-09-30 13F THERMO FISHER SCIENTIFIC COM Call 20,100 -14.47 12,433 -4.32 n/a n/a n/a
2024-08-14 2024-06-30 13F THERMO FISHER SCIENTIFIC COM Call 23,500 -36.66 12,996 -39.73 n/a n/a n/a
2024-05-15 2024-03-31 13F THERMO FISHER SCIENTIFIC COM Call 37,100 47.22 21,563 61.21 n/a n/a n/a
2024-02-14 2023-12-31 13F THERMO FISHER SCIENTIFIC COM Call 25,200 -5.26 13,376 -0.66 n/a n/a n/a
2023-11-21 2023-09-30 13F/A THERMO FISHER SCIENTIFIC COM Call 26,600 60.24 13,464 55.46 n/a n/a n/a
2023-11-14 2023-09-30 13F THERMO FISHER SCIENTIFIC COM Call 26,600 13,464 n/a n/a n/a
2023-08-14 2023-06-30 13F THERMO FISHER SCIENTIFIC COM Call 16,600 144.12 8,661 121.00 n/a n/a n/a
2023-05-15 2023-03-31 13F THERMO FISHER SCIENTIFIC COM Call 6,800 209.09 3,919 223.62 n/a n/a n/a
2023-02-14 2022-12-31 13F THERMO FISHER SCIENTIFIC COM Call 2,200 -59.26 1,212 -55.79 n/a n/a n/a
2022-11-14 2022-09-30 13F THERMO FISHER SCIENTIFIC COM Call 5,400 2,739 n/a n/a n/a
2020-05-15 2020-03-31 13F THERMO FISHER SCIENTIFIC COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-02-14 2019-12-31 13F THERMO FISHER SCIENTIFIC COM Call 6,100 -84.03 1,982 -82.19 n/a n/a n/a
2019-11-14 2019-09-30 13F THERMO FISHER SCIENTIFIC COM Call 38,200 122.09 11,127 120.29 n/a n/a n/a
2019-08-14 2019-06-30 13F THERMO FISHER SCIENTIFIC COM Call 17,200 84.95 5,051 98.39 n/a n/a n/a
2019-08-14 2019-03-31 13F/A THERMO FISHER SCIENTIFIC COM Call 9,300 2,546 n/a n/a n/a
2019-05-15 2019-03-31 13F THERMO FISHER SCIENTIFIC COM Call 9,300 2,546 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
(%)
2026-05-13 2026-03-31 13F/A THERMO FISHER SCIENTIFIC COM Put 2,200 -95.69 1,081 -96.34 n/a n/a n/a
2026-05-08 2026-03-31 13F THERMO FISHER SCIENTIFIC COM Put 2,200 1,081 n/a n/a n/a
2026-02-13 2025-12-31 13F THERMO FISHER SCIENTIFIC COM Put 51,000 140.57 29,552 187.41 n/a n/a n/a
2025-11-14 2025-09-30 13F THERMO FISHER SCIENTIFIC COM Put 21,200 -39.94 10,282 -28.16 n/a n/a n/a
2025-08-13 2025-06-30 13F THERMO FISHER SCIENTIFIC COM Put 35,300 283.70 14,313 212.69 n/a n/a n/a
2025-05-14 2025-03-31 13F THERMO FISHER SCIENTIFIC COM Put 9,200 -75.85 4,578 -76.91 n/a n/a n/a
2025-02-13 2024-12-31 13F THERMO FISHER SCIENTIFIC COM Put 38,100 -15.52 19,821 -28.95 n/a n/a n/a
2024-11-14 2024-09-30 13F THERMO FISHER SCIENTIFIC COM Put 45,100 -10.16 27,898 0.49 n/a n/a n/a
2024-08-14 2024-06-30 13F THERMO FISHER SCIENTIFIC COM Put 50,200 7.73 27,761 2.50 n/a n/a n/a
2024-05-15 2024-03-31 13F THERMO FISHER SCIENTIFIC COM Put 46,600 24.27 27,084 36.07 n/a n/a n/a
2024-02-14 2023-12-31 13F THERMO FISHER SCIENTIFIC COM Put 37,500 22.95 19,905 28.93 n/a n/a n/a
2023-11-21 2023-09-30 13F/A THERMO FISHER SCIENTIFIC COM Put 30,500 48.78 15,438 44.35 n/a n/a n/a
2023-11-14 2023-09-30 13F THERMO FISHER SCIENTIFIC COM Put 30,500 15,438 n/a n/a n/a
2023-08-14 2023-06-30 13F THERMO FISHER SCIENTIFIC COM Put 20,500 502.94 10,696 445.94 n/a n/a n/a
2023-05-15 2023-03-31 13F THERMO FISHER SCIENTIFIC COM Put 3,400 30.77 1,960 36.90 n/a n/a n/a
2023-02-14 2022-12-31 13F THERMO FISHER SCIENTIFIC COM Put 2,600 -23.53 1,432 -17.00 n/a n/a n/a
2022-11-14 2022-09-30 13F THERMO FISHER SCIENTIFIC COM Put 3,400 1,724 n/a n/a n/a
2020-05-15 2020-03-31 13F THERMO FISHER SCIENTIFIC COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-02-14 2019-12-31 13F THERMO FISHER SCIENTIFIC COM Put 1,300 -75.93 422 -73.17 n/a n/a n/a
2019-11-14 2019-09-30 13F THERMO FISHER SCIENTIFIC COM Put 5,400 1,573 n/a n/a n/a
2019-08-14 2019-06-30 13F THERMO FISHER SCIENTIFIC COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-08-14 2019-03-31 13F/A THERMO FISHER SCIENTIFIC COM Put 3,700 1,013 n/a n/a n/a
2019-05-15 2019-03-31 13F THERMO FISHER SCIENTIFIC COM Put 3,700 1,013 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.