Comfort Systems USA, Inc.
MX ˙ BMV ˙ US1999081045
SecurityMX:FIX / Comfort Systems USA, Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership387 shares
Latest Disclosed Value $ 533,669
Simplex Trading, Llc ownership in FIX / Comfort Systems USA, Inc.

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 387 shares of Comfort Systems USA, Inc. (MX:FIX) valued at $533,669 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 2,338 shares of Comfort Systems USA, Inc.. This represents a change in shares of -83.45% during the quarter.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (FIX) in the form of stock options. The firm currently holds call options representing 4,100 of underlying shares valued at $5,653,859 USD and put options representing 3,200 of underlying shares valued at $4,412,768 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:FIX / Comfort Systems USA, 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 COMFORT SYS USA COM 199908104 387 -1,951 -83.45 534 -75.57 0.0002
2026-02-11 2025-12-31 13F COMFORT SYS USA COM 199908104 2,338 1,321 129.89 2,182 0.0012
2025-11-12 2025-09-30 13F COMFORT SYS USA COM 199908104 1,017 431 73.55 1 0.0004
2025-08-05 2025-06-30 13F COMFORT SYS USA COM 199908104 586 -1,281 -68.61 0 0.0002
2025-05-12 2025-03-31 13F COMFORT SYS USA COM 199908104 1,867 787 72.87 1 0.0004
2025-02-11 2024-12-31 13F COMFORT SYS USA COM 199908104 1,080 -480 -30.77 0 0.0003
2024-11-08 2024-09-30 13F COMFORT SYS USA COM 199908104 1,560 373 31.42 1 0.0004
2024-07-25 2024-06-30 13F COMFORT SYS USA COM 199908104 1,187 -50 -4.04 0 0.0002
2024-04-25 2024-03-31 13F COMFORT SYS USA COM 199908104 1,237 1,237 0 0.0002
2024-02-02 2023-12-31 13F COMFORT SYS USA COM 199908104 0 -244 -100.00 0 0.0000
2023-11-01 2023-09-30 13F COMFORT SYS USA COM 199908104 244 -9 -3.56 0 0.0000
2023-08-04 2023-06-30 13F COMFORT SYS USA COM 199908104 253 -823 -76.49 0 0.0000
2023-04-27 2023-03-31 13F COMFORT SYS USA COM 199908104 1,076 -1,729 -61.64 0 0.0001
2023-02-02 2022-12-31 13F COMFORT SYS USA COM 199908104 2,805 1,761 168.68 0 -100.00 0.0004
2022-11-04 2022-09-30 13F COMFORT SYS USA COM 199908104 1,044 1,044 101 0.0001
2022-08-03 2022-06-30 13F COMFORT SYS USA COM 199908104 0 -11 -100.00 0 0.0000
2022-05-02 2022-03-31 13F COMFORT SYS USA COM 199908104 11 -1,072 -98.98 0 -100.00
2022-02-23 2021-12-31 13F/A-1 COMFORT SYS USA COM 199908104 1,083 860 385.65 107 529.41 0.0001
2022-02-04 2021-12-31 13F COMFORT SYS USA COM 199908104 223 0 17 0.0000
2021-10-28 2021-09-30 13F COMFORT SYS USA COM 199908104 223 0 0.00 17 0.00 0.0000
2021-08-12 2021-06-30 13F COMFORT SYS USA COM 199908104 223 -1,254 -84.90 17 -84.55 0.0000
2021-04-26 2021-03-31 13F COMFORT SYS USA COM 199908104 1,477 108 7.89 110 52.78 0.0002
2021-02-02 2020-12-31 13F COMFORT SYS USA COM 199908104 1,369 1,369 -7.31 72 -34.55 0.0001
2020-10-14 2020-09-30 13F COMFORT SYS USA COM 199908104 0 -134 -100.00 0 -100.00
2020-07-13 2020-06-30 13F COMFORT SYS USA COM 199908104 134 -638 -82.64 5 -82.14 0.0000
2020-04-29 2020-03-31 13F COMFORT SYS USA COM 199908104 772 456 144.30 28 86.67 0.0000
2020-02-05 2019-12-31 13F COMFORT SYS USA COM 199908104 316 -169 -34.85 15 -28.57 0.0000
2019-10-15 2019-09-30 13F COMFORT SYS USA COM 199908104 485 274 129.86 21 110.00 0.0001
2019-07-26 2019-06-30 13F COMFORT SYS USA COM 199908104 211 211 -56.49 10 -52.38 0.0000
2018-10-23 2018-09-30 13F COMFORT SYS USA COM 199908104 0 -379 -100.00 0 -100.00
2018-07-30 2018-06-30 13F COMFORT SYS USA COM 199908104 379 379 17 0.0001
2018-04-26 2018-03-31 13F COMFORT SYS USA COM 199908104 0 -100 -100.00 0 -100.00
2018-01-10 2017-12-31 13F COMFORT SYS USA COM 199908104 100 100 4 0.0002
2017-10-25 2017-09-30 13F COMFORT SYS USA COM 199908104 0 -4,552 -100.00 0 -100.00
2017-07-12 2017-06-30 13F COMFORT SYS USA COM 199908104 4,552 -2,223 -32.81 168 -32.26 0.0073
2017-04-21 2017-03-31 13F COMFORT SYS USA COM 199908104 6,775 6,775 48.84 248 47.62 0.0107
2017-01-11 2016-12-31 13F COMFORT SYS USA COM 199908104 0 -199 -100.00 0 -100.00
2016-10-07 2016-09-30 13F COMFORT SYS USA COM 199908104 199 199 0.00 5 0.0003
2015-07-08 2015-06-30 13F COMFORT SYS USA COM 199908104 0 -360 -100.00 0 -100.00
2015-04-21 2015-03-31 13F COMFORT SYS USA COM 199908104 360 360 7 0.0008
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 COMFORT SYS USA CALL Call 4,100 -12.77 5,654 28.89 n/a n/a n/a
2026-02-11 2025-12-31 13F COMFORT SYS USA CALL Call 4,700 487.50 4,386 n/a n/a n/a
2025-11-12 2025-09-30 13F COMFORT SYS USA CALL Call 800 -80.00 1 -100.00 n/a n/a n/a
2025-08-05 2025-06-30 13F COMFORT SYS USA CALL Call 4,000 -56.04 2 0.00 n/a n/a n/a
2025-05-12 2025-03-31 13F COMFORT SYS USA CALL Call 9,100 279.17 3 100.00 n/a n/a n/a
2025-02-11 2024-12-31 13F COMFORT SYS USA CALL Call 2,400 -52.94 1 0.00 n/a n/a n/a
2024-11-08 2024-09-30 13F COMFORT SYS USA CALL Call 5,100 -46.88 2 -50.00 n/a n/a n/a
2024-07-25 2024-06-30 13F COMFORT SYS USA CALL Call 9,600 -66.55 3 -77.78 n/a n/a n/a
2024-04-25 2024-03-31 13F COMFORT SYS USA CALL Call 28,700 370.49 9 800.00 n/a n/a n/a
2024-02-02 2023-12-31 13F COMFORT SYS USA CALL Call 6,100 -45.54 1 0.00 n/a n/a n/a
2023-11-01 2023-09-30 13F COMFORT SYS USA CALL Call 11,200 1,300.00 2 n/a n/a n/a
2023-08-04 2023-06-30 13F COMFORT SYS USA CALL Call 800 700.00 0 n/a n/a n/a
2023-04-27 2023-03-31 13F COMFORT SYS USA CALL Call 100 0.00 0 n/a n/a n/a
2023-02-02 2022-12-31 13F COMFORT SYS USA CALL Call 100 0.00 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F COMFORT SYS USA CALL Call 100 9 n/a n/a n/a
2022-05-02 2022-03-31 13F COMFORT SYS USA CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-02-23 2021-12-31 13F/A COMFORT SYS USA CALL Call 200 -93.75 19 -92.49 n/a n/a n/a
2022-02-04 2021-12-31 13F COMFORT SYS USA CALL Call 3,200 253 n/a n/a n/a
2021-10-28 2021-09-30 13F COMFORT SYS USA CALL Call 3,200 0.00 253 0.40 n/a n/a n/a
2021-08-12 2021-06-30 13F COMFORT SYS USA CALL Call 3,200 24,515.38 252 159.79 n/a n/a n/a
2021-04-26 2021-03-31 13F COMFORT SYS USA CALL Call 13 -64.86 97 -50.00 n/a n/a n/a
2021-02-02 2020-12-31 13F COMFORT SYS USA CALL Call 37 2.78 194 4.86 n/a n/a n/a
2020-10-14 2020-09-30 13F COMFORT SYS USA CALL Call 36 -2.70 185 -4.64 n/a n/a n/a
2020-07-13 2020-06-30 13F COMFORT SYS USA CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-04-29 2020-03-31 13F COMFORT SYS USA CALL Call 8 -81.82 29 -86.76 n/a n/a n/a
2020-02-05 2019-12-31 13F COMFORT SYS USA CALL Call 44 15.79 219 30.36 n/a n/a n/a
2019-10-15 2019-09-30 13F COMFORT SYS USA CALL Call 38 1,166.67 168 1,020.00 n/a n/a n/a
2019-07-26 2019-06-30 13F COMFORT SYS USA CALL Call 3 -50.00 15 -51.61 n/a n/a n/a
2019-04-18 2019-03-31 13F COMFORT SYS USA CALL Call 6 -68.42 31 -62.20 n/a n/a n/a
2019-01-16 2018-12-31 13F COMFORT SYS USA CALL Call 19 216.67 82 164.52 n/a n/a n/a
2018-10-23 2018-09-30 13F COMFORT SYS USA CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-07-30 2018-06-30 13F COMFORT SYS USA CALL Call 13 59 n/a n/a n/a
2017-07-12 2017-06-30 13F COMFORT SYS USA CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-04-21 2017-03-31 13F COMFORT SYS USA CALL Call 3 -85.71 0 -100.00 n/a n/a n/a
2017-01-11 2016-12-31 13F COMFORT SYS USA CALL Call 21 2,000.00 4 n/a n/a n/a
2016-10-07 2016-09-30 13F COMFORT SYS USA CALL Call 1 -75.00 0 -100.00 n/a n/a n/a
2016-07-18 2016-06-30 13F COMFORT SYS USA CALL Call 4 -20.00 0 -100.00 n/a n/a n/a
2016-04-14 2016-03-31 13F COMFORT SYS USA CALL Call 5 -83.87 1 n/a n/a n/a
2016-01-20 2015-12-31 13F COMFORT SYS USA CALL Call 31 -65.93 0 -100.00 n/a n/a n/a
2015-10-08 2015-09-30 13F COMFORT SYS USA CALL Call 91 51.67 12 20.00 n/a n/a n/a
2015-07-08 2015-06-30 13F COMFORT SYS USA CALL Call 60 10 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
(%)
2026-05-14 2026-03-31 13F COMFORT SYS USA PUT Put 3,200 -37.25 4,413 -7.29 n/a n/a n/a
2026-02-11 2025-12-31 13F COMFORT SYS USA PUT Put 5,100 200.00 4,760 475,800.00 n/a n/a n/a
2025-11-12 2025-09-30 13F COMFORT SYS USA PUT Put 1,700 -39.29 1 0.00 n/a n/a n/a
2025-08-05 2025-06-30 13F COMFORT SYS USA PUT Put 2,800 -68.89 2 -50.00 n/a n/a n/a
2025-05-12 2025-03-31 13F COMFORT SYS USA PUT Put 9,000 80.00 3 0.00 n/a n/a n/a
2025-02-11 2024-12-31 13F COMFORT SYS USA PUT Put 5,000 51.52 2 100.00 n/a n/a n/a
2024-11-08 2024-09-30 13F COMFORT SYS USA PUT Put 3,300 200.00 1 n/a n/a n/a
2024-07-25 2024-06-30 13F COMFORT SYS USA PUT Put 1,100 -82.54 0 -100.00 n/a n/a n/a
2024-04-25 2024-03-31 13F COMFORT SYS USA PUT Put 6,300 600.00 2 n/a n/a n/a
2024-02-02 2023-12-31 13F COMFORT SYS USA PUT Put 900 0 n/a n/a n/a
2023-11-01 2023-09-30 13F COMFORT SYS USA PUT Put 0 -100.00 0 n/a n/a n/a
2023-08-04 2023-06-30 13F COMFORT SYS USA PUT Put 800 0.00 0 n/a n/a n/a
2023-04-27 2023-03-31 13F COMFORT SYS USA PUT Put 800 0 n/a n/a n/a
2023-02-02 2022-12-31 13F COMFORT SYS USA PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F COMFORT SYS USA PUT Put 2,200 1,000.00 214 1,237.50 n/a n/a n/a
2022-08-03 2022-06-30 13F COMFORT SYS USA PUT Put 200 0.00 16 -5.88 n/a n/a n/a
2022-05-02 2022-03-31 13F COMFORT SYS USA PUT Put 200 -66.67 17 -71.19 n/a n/a n/a
2022-02-23 2021-12-31 13F/A COMFORT SYS USA PUT Put 600 59 n/a n/a n/a
2021-08-12 2021-06-30 13F COMFORT SYS USA PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-04-26 2021-03-31 13F COMFORT SYS USA PUT Put 25 257.14 186 416.67 n/a n/a n/a
2021-02-02 2020-12-31 13F COMFORT SYS USA PUT Put 7 -80.56 36 -80.54 n/a n/a n/a
2020-10-14 2020-09-30 13F COMFORT SYS USA PUT Put 36 260.00 185 362.50 n/a n/a n/a
2020-07-13 2020-06-30 13F COMFORT SYS USA PUT Put 10 400.00 40 471.43 n/a n/a n/a
2020-04-29 2020-03-31 13F COMFORT SYS USA PUT Put 2 -66.67 7 -75.86 n/a n/a n/a
2020-02-05 2019-12-31 13F COMFORT SYS USA PUT Put 6 -76.92 29 -74.56 n/a n/a n/a
2019-10-15 2019-09-30 13F COMFORT SYS USA PUT Put 26 271.43 114 225.71 n/a n/a n/a
2019-07-26 2019-06-30 13F COMFORT SYS USA PUT Put 7 -82.93 35 -83.64 n/a n/a n/a
2019-04-18 2019-03-31 13F COMFORT SYS USA PUT Put 41 1,950.00 214 2,575.00 n/a n/a n/a
2019-01-16 2018-12-31 13F COMFORT SYS USA PUT Put 2 100.00 8 60.00 n/a n/a n/a
2018-10-23 2018-09-30 13F COMFORT SYS USA PUT Put 1 -50.00 5 -37.50 n/a n/a n/a
2018-07-30 2018-06-30 13F COMFORT SYS USA PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2018-04-26 2018-03-31 13F COMFORT SYS USA PUT Put 1 0.00 0 n/a n/a n/a
2018-01-10 2017-12-31 13F COMFORT SYS USA PUT Put 1 0.00 0 n/a n/a n/a
2017-01-11 2016-12-31 13F COMFORT SYS USA PUT Put 0 -100.00 0 n/a n/a n/a
2016-10-07 2016-09-30 13F COMFORT SYS USA PUT Put 2 0 n/a n/a n/a
2016-04-14 2016-03-31 13F COMFORT SYS USA PUT Put 0 -100.00 0 n/a n/a n/a
2016-01-20 2015-12-31 13F COMFORT SYS USA PUT Put 8 166.67 0 n/a n/a n/a
2015-10-08 2015-09-30 13F COMFORT SYS USA PUT Put 3 0 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.