Comfort Systems USA, Inc.
MX ˙ BMV ˙ US1999081045
SecurityMX:FIX / Comfort Systems USA, Inc.
InstitutionRhumbline Advisers
Latest Disclosed Ownership66,597 shares
Latest Disclosed Value $ 91,836,434
Rhumbline Advisers reports 0.87% decrease in ownership of FIX / Comfort Systems USA, Inc.

On May 12, 2026 - Rhumbline Advisers filed a 13F-HR form disclosing ownership of 66,597 shares of Comfort Systems USA, Inc. (MX:FIX) valued at $91,836,434 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 67,179 shares of Comfort Systems USA, Inc.. This represents a change in shares of -0.87% 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)
2026-05-12 2026-03-31 13F COMFORT SYS USA INC COM COM 199908104 66,597 -582 -0.87 91,836 46.48 0.0786
2026-02-13 2025-12-31 13F COMFORT SYS USA INC COM COM 199908104 67,179 -29,484 -30.50 62,697 -21.40 0.0507
2025-11-06 2025-09-30 13F COMFORT SYS USA INC COM COM 199908104 96,663 -1,732 -1.76 79,764 51.18 0.0641
2025-08-12 2025-06-30 13F COMFORT SYS USA INC COM COM 199908104 98,395 -1,365 -1.37 52,760 64.08 0.0452
2025-05-29 2025-03-31 13F/A-1 COMFORT SYS USA INC COM COM 199908104 99,760 -959 -0.95 32,156 -24.71 0.0301
2025-04-08 2025-03-31 13F COMFORT SYS USA INC COM COM 199908104 99,760 -959 32,156 0.0301
2025-05-29 2024-12-31 13F/A-1 COMFORT SYS USA INC COM COM 199908104 100,719 328 0.33 42,711 8.99 0.0382
2025-01-30 2024-12-31 13F COMFORT SYS USA INC COM COM 199908104 100,719 328 42,711 0.0382
2024-11-12 2024-09-30 13F COMFORT SYS USA INC COM COM 199908104 100,391 -1,362 -1.34 39,188 26.63 0.0354
2024-08-01 2024-06-30 13F COMFORT SYS USA INC COM COM 199908104 101,753 -8,107 -7.38 30,945 -11.34 0.0291
2024-05-09 2024-03-31 13F COMFORT SYS USA INC COM COM 199908104 109,860 1,198 1.10 34,904 56.18 0.0335
2024-02-08 2023-12-31 13F COMFORT SYS USA INC COM COM 199908104 108,662 6,765 6.64 22,348 28.70 0.0234
2023-11-09 2023-09-30 13F COMFORT SYS USA INC COM COM 199908104 101,897 -1,431 -1.38 17,364 2.35 0.0202
2023-08-08 2023-06-30 13F COMFORT SYS USA INC COM COM 199908104 103,328 -106 -0.10 16,966 113,006.67 0.0190
2023-05-11 2023-03-31 13F COMFORT SYS USA INC COM COM 199908104 103,434 4,993 5.07 15 -99.87 0.0186
2023-02-14 2022-12-31 13F COMFORT SYS USA INC COM COM 199908104 98,441 1,774 1.84 11,329 20.41 0.0152
2022-11-10 2022-09-30 13F COMFORT SYS USA INC COM COM 199908104 96,667 4,409 4.78 9,409 22.66 0.0140
2022-08-11 2022-06-30 13F COMFORT SYS USA INC COM COM 199908104 92,258 3,871 4.38 7,671 -2.49 0.0112
2022-05-12 2022-03-31 13F COMFORT SYS USA INC COM COM 199908104 88,387 5,394 6.50 7,867 -4.19 0.0101
2022-02-10 2021-12-31 13F COMFORT SYS USA INC COM COM 199908104 82,993 -996 -1.19 8,211 37.08 0.0101
2021-11-12 2021-09-30 13F COMFORT SYS USA INC COM COM 199908104 83,989 -13,528 -13.87 5,990 -22.04 0.0081
2021-08-05 2021-06-30 13F COMFORT SYS USA INC COM COM 199908104 97,517 -14,388 -12.86 7,683 -8.17 0.0101
2021-05-06 2021-03-31 13F COMFORT SYS USA INC COM COM 199908104 111,905 -35 -0.03 8,367 41.93 0.0114
2021-02-10 2020-12-31 13F COMFORT SYS USA INC COM COM 199908104 111,940 5,235 4.91 5,895 7.26 0.0081
2020-11-12 2020-09-30 13F COMFORT SYS USA INC COM COM 199908104 106,705 -12,525 -10.50 5,496 13.11 0.0086
2020-08-13 2020-06-30 13F COMFORT SYS USA INC COM COM 199908104 119,230 237 0.20 4,859 11.73 0.0081
2020-05-06 2020-03-31 13F COMFORT SYS USA INC COM COM 199908104 118,993 1,710 1.46 4,349 -25.62 0.0091
2020-02-05 2019-12-31 13F COMFORT SYS USA INC COM COM 199908104 117,283 7,882 7.20 5,847 20.83 0.0098
2019-10-23 2019-09-30 13F COMFORT SYS USA INC COM COM 199908104 109,401 1,156 1.07 4,839 -12.32 0.0088
2019-08-14 2019-06-30 13F COMFORT SYS USA INC COM COM 199908104 108,245 2,914 2.77 5,519 0.02 0.0104
2019-05-01 2019-03-31 13F COMFORT SYS USA INC COM COM 199908104 105,331 -5,342 -4.83 5,518 14.15 0.0107
2019-01-31 2018-12-31 13F COMFORT SYS USA INC COM COM 199908104 110,673 17,962 19.37 4,834 -7.55 0.0105
2018-11-07 2018-09-30 13F COMFORT SYS USA INC COM COM 199908104 92,711 4,343 4.91 5,229 29.21 0.0101
2018-08-06 2018-06-30 13F COMFORT SYS USA INC COM COM 199908104 88,368 1,566 1.80 4,047 13.01 0.0082
2018-05-02 2018-03-31 13F COMFORT SYS USA INC COM COM 199908104 86,802 1,757 2.07 3,581 -3.53 0.0075
2018-02-09 2017-12-31 13F COMFORT SYS USA INC COM COM 199908104 85,045 12,231 16.80 3,712 42.82 0.0075
2017-11-06 2017-09-30 13F COMFORT SYS USA INC COM COM 199908104 72,814 1,625 2.28 2,599 -1.59 0.0057
2017-08-02 2017-06-30 13F COMFORT SYS USA INC COM COM 199908104 71,189 -288 -0.40 2,641 0.80 0.0060
2017-05-02 2017-03-31 13F COMFORT SYS USA INC COM COM 199908104 71,477 20,825 41.11 2,620 55.31 0.0061
2017-01-27 2016-12-31 13F COMFORT SYS USA INC COM COM 199908104 50,652 2,163 4.46 1,687 18.72 0.0043
2016-11-08 2016-09-30 13F COMFORT SYS USA INC COM COM 199908104 48,489 1,920 4.12 1,421 -6.33 0.0039
2016-08-11 2016-06-30 13F COMFORT SYS USA INC COM COM 199908104 46,569 484 1.05 1,517 3.62 0.0045
2016-05-02 2016-03-31 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 46,085 885 1.96 1,464 13.93 0.0045
2016-02-03 2015-12-31 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 45,200 -95 -0.21 1,285 4.05 0.0041
2015-11-04 2015-09-30 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 45,295 975 2.20 1,235 21.44 0.0042
2015-08-04 2015-06-30 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 44,320 -17,115 -27.86 1,017 -21.35 0.0032
2015-05-12 2015-03-31 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 61,435 2,150 3.63 1,293 27.39 0.0037
2015-02-06 2014-12-31 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 59,285 6,995 13.38 1,015 43.16 0.0029
2014-11-12 2014-09-30 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 52,290 0 0.00 709 -14.16 0.0021
2014-08-06 2014-06-30 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 52,290 -363 -0.69 826 2.99 0.0024
2014-05-06 2014-03-31 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 52,653 -1,720 -3.16 802 -23.91 0.0024
2014-02-03 2013-12-31 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 54,373 -3,010 -5.25 1,054 9.22 0.0031
2013-11-05 2013-09-30 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 57,383 -592 -1.02 965 11.56 0.0030
2013-08-07 2013-06-30 13F COMFORT SYSTEMS USA INC COMMON COM 199908104 57,975 57,975 865 0.0028
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.