Comfort Systems USA, Inc.
MX ˙ BMV ˙ US1999081045
SecurityMX:FIX / Comfort Systems USA, Inc.
InstitutionRenaissance Technologies Llc
ManagerJames Simons
Latest Disclosed Ownership56,660 shares
Latest Disclosed Value $ 78,133,573
Renaissance Technologies Llc reports 4.96% increase in ownership of FIX / Comfort Systems USA, Inc.

On May 14, 2026 - Renaissance Technologies Llc filed a 13F-HR form disclosing ownership of 56,660 shares of Comfort Systems USA, Inc. (MX:FIX) valued at $78,133,573 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 53,980 shares of Comfort Systems USA, Inc.. This represents a change in shares of 4.96% 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)
2026-05-14 2026-03-31 13F COMFORT SYS USA COM 199908104 56,660 2,680 4.96 78,134 55.09 0.1222
2026-02-12 2025-12-31 13F COMFORT SYS USA COM 199908104 53,980 3,580 7.10 50,379 21.13 0.0782
2025-11-13 2025-09-30 13F COMFORT SYS USA COM 199908104 50,400 -79,900 -61.32 41,589 -40.47 0.0549
2025-08-13 2025-06-30 13F COMFORT SYS USA COM 199908104 130,300 -900 -0.69 69,868 65.22 0.0929
2025-05-14 2025-03-31 13F COMFORT SYS USA COM 199908104 131,200 79,900 155.75 42,290 94.40 0.0640
2025-02-13 2024-12-31 13F COMFORT SYS USA COM 199908104 51,300 -42,700 -45.43 21,754 -40.71 0.0322
2024-11-13 2024-09-30 13F COMFORT SYS USA COM 199908104 94,000 60,200 178.11 36,693 256.96 0.0552
2024-08-09 2024-06-30 13F COMFORT SYS USA COM 199908104 33,800 11,800 53.64 10,279 171,216.67 0.0174
2024-05-13 2024-03-31 13F COMFORT SYS USA COM 199908104 22,000 -14,600 -39.89 7 -14.29 0.0110
2024-02-13 2023-12-31 13F COMFORT SYS USA COM 199908104 36,600 36,600 8 0.0117
2023-11-14 2023-09-30 13F COMFORT SYS USA COM 199908104 0 -24,000 -100.00 0 -100.00
2023-08-11 2023-06-30 13F COMFORT SYS USA COM 199908104 24,000 -77,200 -76.28 4 -78.57 0.0057
2023-05-12 2023-03-31 13F COMFORT SYS USA COM 199908104 101,200 68,900 213.31 15 366.67 0.0196
2023-02-13 2022-12-31 13F COMFORT SYS USA COM 199908104 32,300 32,300 4 0.0051
2022-08-12 2022-06-30 13F COMFORT SYS USA COM 199908104 0 -39,800 -100.00 0 -100.00
2022-05-13 2022-03-31 13F COMFORT SYS USA COM 199908104 39,800 39,800 3,543 0.0042
2022-02-11 2021-12-31 13F COMFORT SYS USA COM 199908104 0 -50,600 -100.00 0 -100.00
2021-11-12 2021-09-30 13F COMFORT SYS USA COM 199908104 50,600 -3,774 -6.94 3,609 -15.76 0.0047
2021-08-13 2021-06-30 13F COMFORT SYS USA COM 199908104 54,374 -42,326 -43.77 4,284 -40.75 0.0053
2021-05-13 2021-03-31 13F COMFORT SYS USA COM 199908104 96,700 8,800 10.01 7,230 56.19 0.0090
2021-02-10 2020-12-31 13F COMFORT SYS USA COM 199908104 87,900 -7,300 -7.67 4,629 -5.61 0.0050
2020-11-13 2020-09-30 13F COMFORT SYS USA COM 199908104 95,200 -3,400 -3.45 4,904 22.05 0.0049
2020-08-13 2020-06-30 13F COMFORT SYS USA COM 199908104 98,600 77,000 356.48 4,018 409.25 0.0035
2020-05-14 2020-03-31 13F COMFORT SYS USA COM 199908104 21,600 21,600 -78.09 789 -80.36 0.0008
2019-11-13 2019-09-30 13F COMFORT SYS USA COM 199908104 0 -127,480 -100.00 0 -100.00
2019-08-12 2019-06-30 13F COMFORT SYS USA COM 199908104 127,480 -283,400 -68.97 6,500 -69.80 0.0057
2019-05-14 2019-03-31 13F COMFORT SYS USA COM 199908104 410,880 -206,100 -33.40 21,526 -20.13 0.0196
2019-02-12 2018-12-31 13F COMFORT SYS USA COM 199908104 616,980 -70,020 -10.19 26,950 -30.45 0.0295
2018-11-13 2018-09-30 13F COMFORT SYS USA COM 199908104 687,000 -100 -0.01 38,747 23.13 0.0398
2018-08-13 2018-06-30 13F/A-1 COMFORT SYS USA COM 199908104 687,100 19,400 2.91 31,469 14.25 0.0343
2018-08-13 2018-06-30 13F COMFORT SYS USA COM 199908104 667,700 27,543
2018-05-14 2018-03-31 13F COMFORT SYS USA COM 199908104 667,700 100 0.01 27,543 -5.48 0.0301
2018-02-13 2017-12-31 13F COMFORT SYS USA COM 199908104 667,600 -85,500 -11.35 29,141 8.39 0.0321
2017-11-13 2017-09-30 13F COMFORT SYS USA COM 199908104 753,100 -114,992 -13.25 26,886 -16.52 0.0316
2017-08-11 2017-06-30 13F COMFORT SYS USA COM 199908104 868,092 90,592 11.65 32,206 13.02 0.0411
2017-05-12 2017-03-31 13F COMFORT SYS USA COM 199908104 777,500 30,800 4.12 28,495 14.60 0.0398
2017-02-13 2016-12-31 13F COMFORT SYS USA COM 199908104 746,700 31,200 4.36 24,865 18.57 0.0393
2016-11-14 2016-09-30 13F COMFORT SYS USA COM 199908104 715,500 21,600 3.11 20,971 -7.21 0.0371
2016-08-12 2016-06-30 13F COMFORT SYS USA COM 199908104 693,900 -59,400 -7.89 22,600 -5.57 0.0430
2016-05-13 2016-03-31 13F COMFORT SYS USA COM 199908104 753,300 -13,100 -1.71 23,932 9.88 0.0455
2016-02-11 2015-12-31 13F COMFORT SYS USA COM 199908104 766,400 375,492 96.06 21,781 104.40 0.0475
2015-11-12 2015-09-30 13F COMFORT SYS USA COM 199908104 390,908 267,408 216.52 10,656 276.01 0.0254
2015-08-14 2015-06-30 13F COMFORT SYS USA COM 199908104 123,500 3,787 3.16 2,834 12.50 0.0065
2015-05-13 2015-03-31 13F COMFORT SYS USA COM 199908104 119,713 119,713 -3.07 2,519 -11.12 0.0054
2015-02-13 2014-12-31 13F COMFORT SYS USA COM 199908104 0 -63,900 -100.00 0 -100.00
2014-11-12 2014-09-30 13F COMFORT SYS USA COM 199908104 63,900 8,100 14.52 866 -1.81 0.0024
2014-08-13 2014-06-30 13F COMFORT SYS USA COM 199908104 55,800 -261,297 -82.40 882 -81.75 0.0021
2014-05-14 2014-03-31 13F COMFORT SYS USA COM 199908104 317,097 64,697 25.63 4,833 -1.25 0.0116
2014-02-14 2013-12-31 13F COMFORT SYS USA COM 199908104 252,400 219,000 655.69 4,894 772.37 0.0117
2013-11-13 2013-09-30 13F COMFORT SYS USA COM 199908104 33,400 33,400 561 0.0014
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.