Littelfuse, Inc.
US ˙ NasdaqGS ˙ US5370081045

SecurityLFUS / Littelfuse, Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Simplex Trading, Llc ownership in LFUS / Littelfuse, Inc.

On February 11, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 0 shares of Littelfuse, Inc. (US:LFUS) valued at $0 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 12, 2025 disclosing 979 shares of Littelfuse, Inc.. The current value of the position is $0 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (LFUS) in the form of stock options. The firm currently holds call options representing 400 of underlying shares valued at $135,740 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.

LFUS / Littelfuse, 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)
2026-02-11 2025-12-31 13F LITTELFUSE COM 537008104 0 -979 -100.00 0 0.0000
2025-11-12 2025-09-30 13F LITTELFUSE COM 537008104 979 979 0 0.0001
2025-02-11 2024-12-31 13F LITTELFUSE COM 537008104 0 -1,206 -100.00 0 0.0000
2024-11-08 2024-09-30 13F LITTELFUSE COM 537008104 1,206 1,206 0 0.0002
2024-04-25 2024-03-31 13F LITTELFUSE COM 537008104 0 -93 -100.00 0 0.0000
2024-02-02 2023-12-31 13F LITTELFUSE COM 537008104 93 -243 -72.32 0 0.0000
2023-11-01 2023-09-30 13F LITTELFUSE COM 537008104 336 336 0 0.0001
2023-04-27 2023-03-31 13F LITTELFUSE COM 537008104 0 -29 -100.00 0 0.0000
2023-02-02 2022-12-31 13F LITTELFUSE COM 537008104 29 29 0 0.0000
2022-05-02 2022-03-31 13F LITTELFUSE COM 537008104 0 -156 -100.00 0 -100.00
2022-02-23 2021-12-31 13F/A-1 LITTELFUSE COM 537008104 156 156 49 0.0000
2020-10-14 2020-09-30 13F LITTELFUSE COM 537008104 0 -881 -100.00 0 -100.00
2020-07-13 2020-06-30 13F LITTELFUSE COM 537008104 881 -300 -25.40 150 -4.46 0.0002
2020-04-29 2020-03-31 13F LITTELFUSE COM 537008104 1,181 1,140 2,780.49 157 2,142.86 0.0003
2020-02-05 2019-12-31 13F LITTELFUSE COM 537008104 41 41 7 0.0000
2018-04-26 2018-03-31 13F LITTELFUSE COM 537008104 0 -22 -100.00 0 -100.00
2018-01-10 2017-12-31 13F LITTELFUSE COM 537008104 22 13 144.44 4 300.00 0.0002
2017-10-25 2017-09-30 13F LITTELFUSE COM 537008104 9 -114 -92.68 1 -95.00 0.0000
2017-07-12 2017-06-30 13F LITTELFUSE COM 537008104 123 93 310.00 20 400.00 0.0009
2017-04-21 2017-03-31 13F LITTELFUSE COM 537008104 30 0 0.00 4 0.00 0.0002
2017-01-11 2016-12-31 13F LITTELFUSE COM 537008104 30 -251 -89.32 4 -88.89 0.0002
2016-10-07 2016-09-30 13F LITTELFUSE COM 537008104 281 -185 -39.70 36 -34.55 0.0024
2016-07-18 2016-06-30 13F LITTELFUSE COM 537008104 466 466 0.00 55 0.0037
2016-01-20 2015-12-31 13F LITTELFUSE COM 537008104 0 -2,186 -100.00 0 -100.00
2015-10-08 2015-09-30 13F LITTELFUSE COM 537008104 2,186 2,186 0.00 199 0.0146
2015-07-08 2015-06-30 13F LITTELFUSE COM 537008104 0 -853 -100.00 0 -100.00
2015-04-21 2015-03-31 13F LITTELFUSE COM 537008104 853 853 84 0.0098
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
(%)
2026-05-14 2026-03-31 13F LITTELFUSE CALL Call 400 136 n/a n/a n/a
2025-11-12 2025-09-30 13F LITTELFUSE CALL Call 0 -100.00 0 n/a n/a n/a
2025-08-05 2025-06-30 13F LITTELFUSE CALL Call 700 250.00 0 n/a n/a n/a
2025-05-12 2025-03-31 13F LITTELFUSE CALL Call 200 -66.67 0 n/a n/a n/a
2025-02-11 2024-12-31 13F LITTELFUSE CALL Call 600 500.00 0 n/a n/a n/a
2024-11-08 2024-09-30 13F LITTELFUSE CALL Call 100 -95.83 0 n/a n/a n/a
2024-07-25 2024-06-30 13F LITTELFUSE CALL Call 2,400 1 n/a n/a n/a
2024-04-25 2024-03-31 13F LITTELFUSE CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2024-02-02 2023-12-31 13F LITTELFUSE CALL Call 3,800 0.00 1 n/a n/a n/a
2023-11-01 2023-09-30 13F LITTELFUSE CALL Call 3,800 3,700.00 1 n/a n/a n/a
2023-08-04 2023-06-30 13F LITTELFUSE CALL Call 100 0 n/a n/a n/a
2023-02-02 2022-12-31 13F LITTELFUSE CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F LITTELFUSE CALL Call 300 -50.00 59 -61.18 n/a n/a n/a
2022-08-03 2022-06-30 13F LITTELFUSE CALL Call 600 50.00 152 53.54 n/a n/a n/a
2022-05-02 2022-03-31 13F LITTELFUSE CALL Call 400 100.00 99 94.12 n/a n/a n/a
2022-02-04 2021-12-31 13F LITTELFUSE CALL Call 200 0.00 51 0.00 n/a n/a n/a
2021-10-28 2021-09-30 13F LITTELFUSE CALL Call 200 0.00 51 2.00 n/a n/a n/a
2021-08-12 2021-06-30 13F LITTELFUSE CALL Call 200 19,900.00 50 2,400.00 n/a n/a n/a
2021-04-26 2021-03-31 13F LITTELFUSE CALL Call 1 0.00 2 -92.00 n/a n/a n/a
2021-02-02 2020-12-31 13F LITTELFUSE CALL Call 1 25 n/a n/a n/a
2020-07-13 2020-06-30 13F LITTELFUSE CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-04-29 2020-03-31 13F LITTELFUSE CALL Call 2 0.00 26 -31.58 n/a n/a n/a
2020-02-05 2019-12-31 13F LITTELFUSE CALL Call 2 0.00 38 8.57 n/a n/a n/a
2019-10-15 2019-09-30 13F LITTELFUSE CALL Call 2 35 n/a n/a n/a
2019-01-16 2018-12-31 13F LITTELFUSE CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-10-23 2018-09-30 13F LITTELFUSE CALL Call 9 125.00 178 95.60 n/a n/a n/a
2018-07-30 2018-06-30 13F LITTELFUSE CALL Call 4 91 n/a n/a n/a
2018-04-26 2018-03-31 13F LITTELFUSE CALL Call 0 -100.00 0 n/a n/a n/a
2018-01-10 2017-12-31 13F LITTELFUSE CALL Call 1 0.00 0 n/a n/a n/a
2017-10-25 2017-09-30 13F LITTELFUSE CALL Call 1 0.00 0 n/a n/a n/a
2017-04-21 2017-03-31 13F LITTELFUSE CALL Call 0 -100.00 0 n/a n/a n/a
2017-01-11 2016-12-31 13F LITTELFUSE CALL Call 3 0 n/a n/a n/a
2016-07-18 2016-06-30 13F LITTELFUSE CALL Call 0 -100.00 0 n/a n/a n/a
2016-04-14 2016-03-31 13F LITTELFUSE CALL Call 4 0 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
(%)
2026-02-11 2025-12-31 13F LITTELFUSE PUT Put 0 -100.00 0 n/a n/a n/a
2025-11-12 2025-09-30 13F LITTELFUSE PUT Put 1,000 0 n/a n/a n/a
2023-11-01 2023-09-30 13F LITTELFUSE PUT Put 0 -100.00 0 n/a n/a n/a
2023-08-04 2023-06-30 13F LITTELFUSE PUT Put 100 0 n/a n/a n/a
2023-04-27 2023-03-31 13F LITTELFUSE PUT Put 0 -100.00 0 n/a n/a n/a
2023-02-02 2022-12-31 13F LITTELFUSE PUT Put 100 -66.67 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F LITTELFUSE PUT Put 300 -93.18 59 -94.72 n/a n/a n/a
2022-08-03 2022-06-30 13F LITTELFUSE PUT Put 4,400 10.00 1,117 12.04 n/a n/a n/a
2022-05-02 2022-03-31 13F LITTELFUSE PUT Put 4,000 997 n/a n/a n/a
2020-10-14 2020-09-30 13F LITTELFUSE PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-07-13 2020-06-30 13F LITTELFUSE PUT Put 10 -23.08 170 -1.73 n/a n/a n/a
2020-04-29 2020-03-31 13F LITTELFUSE PUT Put 13 1,200.00 173 810.53 n/a n/a n/a
2020-02-05 2019-12-31 13F LITTELFUSE PUT Put 1 19 n/a n/a n/a
2019-01-16 2018-12-31 13F LITTELFUSE PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2018-10-23 2018-09-30 13F LITTELFUSE PUT Put 74 89.74 1,464 64.68 n/a n/a n/a
2018-07-30 2018-06-30 13F LITTELFUSE PUT Put 39 889 n/a n/a n/a
2018-04-26 2018-03-31 13F LITTELFUSE PUT Put 0 -100.00 0 n/a n/a n/a
2018-01-10 2017-12-31 13F LITTELFUSE PUT Put 1 -97.50 0 n/a n/a n/a
2017-10-25 2017-09-30 13F LITTELFUSE PUT Put 40 1,900.00 0 n/a n/a n/a
2017-07-12 2017-06-30 13F LITTELFUSE PUT Put 2 -81.82 0 n/a n/a n/a
2017-04-21 2017-03-31 13F LITTELFUSE PUT Put 11 0 n/a n/a n/a
2017-01-11 2016-12-31 13F LITTELFUSE PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2016-10-07 2016-09-30 13F LITTELFUSE PUT Put 9 0.00 1 -83.33 n/a n/a n/a
2016-07-18 2016-06-30 13F LITTELFUSE PUT Put 9 6 n/a n/a n/a
2016-01-20 2015-12-31 13F LITTELFUSE PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2015-10-08 2015-09-30 13F LITTELFUSE PUT Put 22 54 n/a n/a n/a
2015-07-08 2015-06-30 13F LITTELFUSE PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2015-04-21 2015-03-31 13F LITTELFUSE PUT Put 37 2 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.