Comfort Systems USA, Inc.
MX ˙ BMV ˙ US1999081045
SecurityMX:FIX / Comfort Systems USA, Inc.
InstitutionMillennium Management Llc
ManagerIsrael Englander
Latest Disclosed Ownership103,313 shares
Latest Disclosed Value $ 142,467,594
Millennium Management Llc ownership in FIX / Comfort Systems USA, Inc.

On May 15, 2026 - Millennium Management Llc filed a 13F-HR form disclosing ownership of 103,313 shares of Comfort Systems USA, Inc. (MX:FIX) valued at $142,467,594 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 62,344 shares of Comfort Systems USA, Inc.. This represents a change in shares of 65.71% during the quarter.

Millennium Management 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 6,600 of underlying shares valued at $9,101,334 USD and put options representing 800 of underlying shares valued at $1,103,192 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)
2026-05-15 2026-03-31 13F COMFORT SYS USA COM 199908104 103,313 40,969 65.71 142,468 144.85 0.0593
2026-02-17 2025-12-31 13F COMFORT SYS USA COM 199908104 62,344 -296,341 -82.62 58,185 -80.34 0.0245
2025-11-14 2025-09-30 13F COMFORT SYS USA COM 199908104 358,685 203,136 130.59 295,980 254.87 0.1263
2025-08-14 2025-06-30 13F COMFORT SYS USA COM 199908104 155,549 -162,303 -51.06 83,407 -18.59 0.0403
2025-05-15 2025-03-31 13F COMFORT SYS USA COM 199908104 317,852 150,547 89.98 102,453 44.41 0.0545
2025-02-14 2024-12-31 13F COMFORT SYS USA COM 199908104 167,305 -7,198 -4.12 70,947 4.15 0.0347
2024-11-14 2024-09-30 13F COMFORT SYS USA COM 199908104 174,503 -168,221 -49.08 68,117 -34.65 0.0323
2024-08-14 2024-06-30 13F COMFORT SYS USA COM 199908104 342,724 283,416 477.87 104,229 453.17 0.0483
2024-05-15 2024-03-31 13F COMFORT SYS USA COM 199908104 59,308 -217,703 -78.59 18,843 -66.93 0.0080
2024-02-14 2023-12-31 13F COMFORT SYS USA COM 199908104 277,011 212,268 327.86 56,973 416.42 0.0246
2023-11-14 2023-09-30 13F COMFORT SYS USA COM 199908104 64,743 -129,697 -66.70 11,033 -65.45 0.0056
2023-08-14 2023-06-30 13F COMFORT SYS USA COM 199908104 194,440 21,982 12.75 31,927 26.84 0.0157
2023-05-15 2023-03-31 13F COMFORT SYS USA COM 199908104 172,458 -65,005 -27.37 25,172 -7.89 0.0144
2023-02-14 2022-12-31 13F COMFORT SYS USA COM 199908104 237,463 182,443 331.59 27,327 410.31 0.0151
2022-11-14 2022-09-30 13F COMFORT SYS USA COM 199908104 55,020 36,054 190.10 5,355 239.57 0.0032
2022-08-15 2022-06-30 13F COMFORT SYS USA COM 199908104 18,966 14,876 363.72 1,577 333.24 0.0010
2022-05-16 2022-03-31 13F COMFORT SYS USA COM 199908104 4,090 -11,999 -74.58 364 -77.14 0.0002
2022-02-14 2021-12-31 13F COMFORT SYS USA COM 199908104 16,089 -47,250 -74.60 1,592 -64.76 0.0008
2021-11-15 2021-09-30 13F COMFORT SYS USA COM 199908104 63,339 13,683 27.56 4,517 15.47 0.0027
2021-08-16 2021-06-30 13F COMFORT SYS USA COM 199908104 49,656 38,023 326.85 3,912 349.66 0.0024
2021-05-17 2021-03-31 13F COMFORT SYS USA COM 199908104 11,633 -76,492 -86.80 870 -81.25 0.0006
2021-02-16 2020-12-31 13F COMFORT SYS USA COM 199908104 88,125 78,156 783.99 4,641 802.92 0.0034
2020-11-16 2020-09-30 13F COMFORT SYS USA COM 199908104 9,969 -127,499 -92.75 514 -90.82 0.0006
2020-08-14 2020-06-30 13F COMFORT SYS USA COM 199908104 137,468 -18,172 -11.68 5,602 -1.53 0.0077
2020-05-14 2020-03-31 13F COMFORT SYS USA COM 199908104 155,640 -202,906 -56.59 5,689 -68.17 0.0128
2020-02-14 2019-12-31 13F COMFORT SYS USA COM 199908104 358,546 2,999 0.84 17,874 13.67 0.0224
2019-11-14 2019-09-30 13F COMFORT SYS USA COM 199908104 355,547 194,723 121.08 15,725 91.77 0.0249
2019-08-15 2019-06-30 13F/A-1 COMFORT SYS USA COM 199908104 160,824 -151,969 -48.58 8,200 -49.96 0.0123
2019-08-14 2019-06-30 13F HENNESSY CAP ACQUSTION UNIT 99/99/9999 199908104 309,377 -3,416 3,196
2019-05-14 2019-03-31 13F COMFORT SYS USA COM 199908104 312,793 -74,024 -19.14 16,387 -3.01 0.0245
2019-02-15 2018-12-31 13F/A-1 COMFORT SYS USA COM 199908104 386,817 16,627 4.49 16,896 -19.08 0.0263
2019-02-14 2018-12-31 13F COMFORT SYS USA COM 199908104 386,817 16,896
2018-11-14 2018-09-30 13F COMFORT SYS USA COM 199908104 370,190 84,903 29.76 20,879 59.80 0.0256
2018-08-14 2018-06-30 13F COMFORT SYS USA COM 199908104 285,287 -10,426 -3.53 13,066 7.12 0.0170
2018-05-15 2018-03-31 13F COMFORT SYS USA COM 199908104 295,713 -45,843 -13.42 12,198 -18.18 0.0163
2018-02-14 2017-12-31 13F COMFORT SYS USA COM 199908104 341,556 271,395 386.82 14,909 495.17 0.0206
2017-11-14 2017-09-30 13F COMFORT SYS USA COM 199908104 70,161 -155,118 -68.86 2,505 -70.03 0.0038
2017-08-14 2017-06-30 13F COMFORT SYS USA COM 199908104 225,279 -119,411 -34.64 8,358 -33.84 0.0149
2017-05-15 2017-03-31 13F COMFORT SYS USA COM 199908104 344,690 166,823 93.79 12,633 113.29 0.0231
2017-02-14 2016-12-31 13F COMFORT SYS USA COM 199908104 177,867 -81,995 -31.55 5,923 -22.24 0.0124
2016-11-14 2016-09-30 13F COMFORT SYS USA COM 199908104 259,862 200,215 335.67 7,617 292.02 0.0128
2016-08-15 2016-06-30 13F COMFORT SYS USA COM 199908104 59,647 -83,383 -58.30 1,943 -57.24 0.0044
2016-05-16 2016-03-31 13F COMFORT SYS USA COM 199908104 143,030 -222,668 -60.89 4,544 -56.28 0.0114
2016-02-16 2015-12-31 13F COMFORT SYS USA COM 199908104 365,698 140,921 62.69 10,393 69.63 0.0218
2015-11-16 2015-09-30 13F COMFORT SYS USA COM 199908104 224,777 73,834 48.92 6,127 76.88 0.0119
2015-08-14 2015-06-30 13F COMFORT SYS USA COM 199908104 150,943 -27,133 -15.24 3,464 -7.55 0.0066
2015-05-15 2015-03-31 13F COMFORT SYS USA COM 199908104 178,076 104,444 141.85 3,747 197.15 0.0070
2015-02-17 2014-12-31 13F COMFORT SYS USA COM 199908104 73,632 73,632 0.00 1,261 0.0027
2014-11-14 2014-09-30 13F COMFORT SYS USA COM 199908104 0 -81,999 -100.00 0 -100.00
2014-08-14 2014-06-30 13F COMFORT SYS USA COM 199908104 81,999 -145,591 -63.97 1,296 -62.63 0.0036
2014-05-15 2014-03-31 13F COMFORT SYS USA COM 199908104 227,590 -2,304 -1.00 3,468 -22.21 0.0101
2014-02-14 2013-12-31 13F COMFORT SYS USA COM 199908104 229,894 179,432 355.58 4,458 425.71 0.0141
2013-11-14 2013-09-30 13F COMFORT SYS USA COM 199908104 50,462 -2,785 -5.23 848 6.80 0.0027
2013-08-14 2013-06-30 13F COMFORT SYS USA COM 199908104 53,247 53,247 794 0.0024
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
(%)
2026-05-15 2026-03-31 13F COMFORT SYS USA COM Call 6,600 9,101 n/a n/a n/a
2026-02-17 2025-12-31 13F COMFORT SYS USA COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-11-14 2025-09-30 13F COMFORT SYS USA COM Call 500 413 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
(%)
2026-05-15 2026-03-31 13F COMFORT SYS USA COM Put 800 -20.00 1,103 18.22 n/a n/a n/a
2026-02-17 2025-12-31 13F COMFORT SYS USA COM Put 1,000 -28.57 933 -19.22 n/a n/a n/a
2025-11-14 2025-09-30 13F COMFORT SYS USA COM Put 1,400 40.00 1,155 115.49 n/a n/a n/a
2025-08-14 2025-06-30 13F COMFORT SYS USA COM Put 1,000 536 n/a n/a n/a
2025-05-15 2025-03-31 13F COMFORT SYS USA COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-14 2024-12-31 13F COMFORT SYS USA COM Put 900 382 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.