Comfort Systems USA, Inc.
MX ˙ BMV ˙ US1999081045
SecurityMX:FIX / Comfort Systems USA, Inc.
InstitutionRussell Investments Group, Ltd.
Latest Disclosed Ownership99,887 shares
Latest Disclosed Value $ 137,682,003
Russell Investments Group, Ltd. reports 1.39% decrease in ownership of FIX / Comfort Systems USA, Inc.

On May 8, 2026 - Russell Investments Group, Ltd. filed a 13F-HR form disclosing ownership of 99,887 shares of Comfort Systems USA, Inc. (MX:FIX) valued at $137,682,003 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 101,295 shares of Comfort Systems USA, Inc.. This represents a change in shares of -1.39% 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)
2026-05-08 2026-03-31 13F COMFORT SYS USA Common Stock 199908104 99,887 -1,408 -1.39 137,682 45.63 0.0142
2026-02-17 2025-12-31 13F COMFORT SYS USA Common Stock 199908104 101,295 -4,704 -4.44 94,546 8.16 0.1030
2025-11-13 2025-09-30 13F COMFORT SYS USA Common Stock 199908104 105,999 -19,730 -15.69 87,415 29.67 0.0992
2025-08-13 2025-06-30 13F COMFORT SYS USA Common Stock 199908104 125,729 1,247 1.00 67,412 67.98 0.0859
2025-05-13 2025-03-31 13F COMFORT SYS USA Common Stock 199908104 124,482 72,061 137.47 40,131 80.33 0.0551
2025-02-13 2024-12-31 13F COMFORT SYS USA Common Stock 199908104 52,421 28,980 123.63 22,254 143.27 0.0307
2024-11-13 2024-09-30 13F COMFORT SYS USA Common Stock 199908104 23,441 -13,233 -36.08 9,149 -18.94 0.0132
2024-08-08 2024-06-30 13F COMFORT SYS USA Common Stock 199908104 36,674 2,049 5.92 11,287 2.58 0.0182
2024-05-08 2024-03-31 13F COMFORT SYS USA Common Stock 199908104 34,625 754 2.23 11,003 57.80 0.0174
2024-02-05 2023-12-31 13F COMFORT SYS USA Common Stock 199908104 33,871 2,483 7.91 6,972 29.25 0.0124
2023-11-13 2023-09-30 13F COMFORT SYS USA INC COM Common Stock 199908104 31,388 7,820 33.18 5,394 39.42 0.0107
2023-08-10 2023-06-30 13F COMFORT SYS USA INC COM Common Stock 199908104 23,568 -3,274 -12.20 3,870 -1.23 0.0075
2023-05-09 2023-03-31 13F COMFORT SYS USA INC COM Common Stock 199908104 26,842 10,361 62.87 3,918 106.59 0.0077
2023-02-08 2022-12-31 13F COMFORT SYSTEMS USA Common Stock 199908104 16,481 4,673 39.57 1,897 65.16 0.0039
2022-11-04 2022-09-30 13F COMFORT SYSTEMS USA Common Stock 199908104 11,808 462 4.07 1,148 21.87 0.0025
2022-07-29 2022-06-30 13F COMFORT SYSTEMS USA Common Stock 199908104 11,346 -113 -0.99 942 -7.56 0.0019
2022-05-05 2022-03-31 13F COMFORT SYSTEMS USA Common Stock 199908104 11,459 2,293 25.02 1,019 12.47 0.0018
2022-01-21 2021-12-31 13F COMFORT SYSTEMS USA Common Stock 199908104 9,166 624 7.31 906 48.77 0.0014
2021-11-08 2021-09-30 13F COMFORT SYSTEMS USA Common Stock 199908104 8,542 -7,943 -48.18 609 -53.05 0.0010
2021-08-04 2021-06-30 13F COMFORT SYSTEMS USA Common Stock 199908104 16,485 -40,830 -71.24 1,297 -69.72 0.0022
2021-05-10 2021-03-31 13F Comfort Systems USA Common Stock 199908104 57,315 44,978 364.58 4,284 561.11 0.0076
2021-02-08 2020-12-31 13F Comfort Systems USA Common Stock 199908104 12,337 -109,036 -89.84 648 -89.63 0.0013
2020-11-09 2020-09-30 13F Comfort Systems USA Common Stock 199908104 121,373 -23,610 -16.28 6,251 5.90 0.0135
2020-08-05 2020-06-30 13F COMFORT SYSTEMS USA Common Stock 199908104 144,983 -222,438 -60.54 5,903 -56.00 0.0132
2020-05-06 2020-03-31 13F/A-1 Comfort Systems USA Common Stock 199908104 367,421 -98,393 -21.12 13,415 -42.22 0.0348
2020-05-06 2020-03-31 13F Comfort Systems USA Common Stock 199908104 367,421 -98,393 13,415 7,326.7391
2020-01-29 2019-12-31 13F Comfort Systems USA Common Stock 199908104 465,814 79,408 20.55 23,219 35.86 0.0432
2019-11-01 2019-09-30 13F Comfort Systems USA Common Stock 199908104 386,406 129,115 50.18 17,090 30.30 0.0332
2019-08-09 2019-06-30 13F Comfort Systems USA Common Stock 199908104 257,291 6,388 2.55 13,116 -0.24 0.0245
2019-05-13 2019-03-31 13F Comfort Systems USA Common Stock 199908104 250,903 8,764 3.62 13,147 24.42 0.0243
2019-02-11 2018-12-31 13F Comfort Systems USA Common Stock 199908104 242,139 27,747 12.94 10,567 -12.52 0.0237
2018-10-26 2018-09-30 13F Comfort Systems USA Common Stock 199908104 214,392 -9,746 -4.35 12,079 17.66 0.0229
2018-08-08 2018-06-30 13F Comfort Systems USA Common Stock 199908104 224,138 -7,675 -3.31 10,266 7.36 0.0214
2018-05-11 2018-03-31 13F COMFORT SYS USA INC COM Common Stocks 199908104 231,813 10,602 4.79 9,562 -1.41 0.0162
2018-02-06 2017-12-31 13F COMFORT SYS USA INC COM Common Stocks 199908104 221,211 -21,561 -8.88 9,699 11.91 0.0163
2017-11-07 2017-09-30 13F COMFORT SYS USA INC COM Common Stocks 199908104 242,772 87,345 56.20 8,667 50.29 0.0148
2017-07-25 2017-06-30 13F COMFORT SYS USA INC COM Common Stocks 199908104 155,427 32,077 26.00 5,767 27.59 0.0102
2017-04-26 2017-03-31 13F COMFORT SYS USA INC COM Common Stocks 199908104 123,350 7,510 6.48 4,520 15.96 0.0083
2017-01-23 2016-12-31 13F COMFORT SYS USA INC COM Common Stocks 199908104 115,840 115,840 3,898 0.0076
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.