Comfort Systems USA, Inc.
MX ˙ BMV ˙ US1999081045
SecurityMX:FIX / Comfort Systems USA, Inc.
InstitutionFmr Llc
Latest Disclosed Ownership1,449,518 shares
Ownership 4.10%
Fmr Llc ownership in FIX / Comfort Systems USA, Inc.

2026-05-06 - Fmr Llc has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 1,449,518 shares of Comfort Systems USA, Inc. (MX:FIX). This represents 4.1 percent ownership of the company. In their previous filing dated 2025-11-05 , Fmr Llc had reported owning 1,892,021 shares, indicating a decrease of -23.39 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date		Effective
Date		Form Prev
Shares		 Latest
Shares		 ΔShares
(Percent)		 Ownership
(Percent)		 ΔOwnership
(Percent)
2026-05-06 2026-05-06 13G/A 1,892,021 1,449,518 -23.39 4.10 -24.07
2025-11-05 2025-11-05 13G 1,892,021 5.40

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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)
2026-05-15 2026-03-31 13F COMFORT SYS USA COM 199908104 1,449,517 -221,194 -13.24 1,998,871 28.19 0.1053
2026-02-17 2025-12-31 13F COMFORT SYS USA COM 199908104 1,670,711 -221,310 -11.70 1,559,258 -0.13 0.0795
2025-11-13 2025-09-30 13F COMFORT SYS USA COM 199908104 1,892,021 321,531 20.47 1,561,258 85.40 0.0812
2025-08-14 2025-06-30 13F COMFORT SYS USA COM 199908104 1,570,490 146,248 10.27 842,113 83.44 0.0475
2025-05-12 2025-03-31 13F COMFORT SYS USA COM 199908104 1,424,242 -272,793 -16.07 459,076 -36.21 0.0293
2025-02-13 2024-12-31 13F COMFORT SYS USA COM 199908104 1,697,035 148,493 9.59 719,645 19.05 0.0429
2024-11-13 2024-09-30 13F COMFORT SYS USA COM 199908104 1,548,542 -156,452 -9.18 604,473 16.58 0.0368
2024-08-13 2024-06-30 13F COMFORT SYS USA COM 199908104 1,704,994 -471,874 -21.68 518,523 -25.03 0.0332
2024-05-13 2024-03-31 13F COMFORT SYS USA COM 199908104 2,176,868 1,460,167 203.73 691,613 369.20 0.0464
2024-02-13 2023-12-31 13F COMFORT SYS USA COM 199908104 716,701 145,923 25.57 147,404 51.55 0.0113
2023-11-13 2023-09-30 13F COMFORT SYS USA COM 199908104 570,778 216,200 60.97 97,266 67.06 0.0084
2023-08-11 2023-06-30 13F COMFORT SYS USA COM 199908104 354,578 -67,711 -16.03 58,222 -5.54 0.0049
2023-08-11 2023-03-31 13F/A-1 COMFORT SYS USA COM 199908104 422,289 -186,796 -30.67 61,637 -12.06 0.0056
2023-05-11 2023-03-31 13F COMFORT SYS USA COM 199908104 422,289 -186,796 61,637 0.0011
2023-02-13 2022-12-31 13F COMFORT SYS USA COM 199908104 609,085 -201,616 -24.87 70,094 -11.17 0.0070
2022-11-10 2022-09-30 13F COMFORT SYS USA COM 199908104 810,701 3,551 0.44 78,905 17.57 0.0082
2022-08-12 2022-06-30 13F COMFORT SYS USA COM 199908104 807,150 187,982 30.36 67,114 21.78 0.0067
2022-05-13 2022-03-31 13F COMFORT SYS USA COM 199908104 619,168 -238,828 -27.84 55,111 -35.08 0.0044
2022-02-14 2021-12-31 13F COMFORT SYS USA COM 199908104 857,996 52,719 6.55 84,891 47.81 0.0063
2022-02-14 2021-09-30 13F/A-1 COMFORT SYS USA COM 199908104 805,277 -95,110 -10.56 57,432 -19.04 0.0046
2021-11-15 2021-09-30 13F COMFORT SYS USA COM 199908104 805,277 -95,110 57,432 0.0009
2021-08-13 2021-06-30 13F COMFORT SYS USA COM 199908104 900,387 -355,063 -28.28 70,942 -24.43 0.0056
2021-05-14 2021-03-31 13F COMFORT SYS USA COM 199908104 1,255,450 -414 -0.03 93,870 41.94 0.0080
2021-02-08 2020-12-31 13F COMFORT SYS USA COM 199908104 1,255,864 70,901 5.98 66,134 8.35 0.0059
2020-11-13 2020-09-30 13F COMFORT SYS USA COM 199908104 1,184,963 209,906 21.53 61,037 53.62 0.0062
2020-08-24 2020-06-30 13F/A-1 COMFORT SYS USA COM 199908104 975,057 40,994 4.39 39,733 16.38 0.0044
2020-08-13 2020-06-30 13F COMFORT SYS USA COM 199908104 975,057 40,994 39,733 976.1235
2020-05-14 2020-03-31 13F COMFORT SYS USA COM 199908104 934,063 13,676 1.49 34,140 -25.59 0.0047
2020-02-07 2019-12-31 13F COMFORT SYS USA COM 199908104 920,387 -182,196 -16.52 45,881 -5.92 0.0051
2019-11-13 2019-09-30 13F COMFORT SYS USA COM 199908104 1,102,583 91,261 9.02 48,767 -5.43 0.0058
2019-08-13 2019-06-30 13F COMFORT SYS USA COM 199908104 1,011,322 -12,223 -1.19 51,567 -3.84 0.0060
2019-05-13 2019-03-31 13F COMFORT SYS USA COM 199908104 1,023,545 -25,430 -2.42 53,624 17.03 0.0064
2019-02-13 2018-12-31 13F COMFORT SYS USA COM 199908104 1,048,975 -215,579 -17.05 45,819 -35.76 0.0063
2018-11-09 2018-09-30 13F COMFORT SYS USA COM 199908104 1,264,554 -56,491 -4.28 71,320 17.88 0.0080
2018-08-10 2018-06-30 13F COMFORT SYS USA COM 199908104 1,321,045 68,900 5.50 60,504 17.14 0.0071
2018-05-14 2018-03-31 13F COMFORT SYS USA COM 199908104 1,252,145 -21,206 -1.67 51,651 -7.07 0.0061
2018-02-12 2017-12-31 13F COMFORT SYS USA COM 199908104 1,273,351 117,128 10.13 55,582 34.66 0.0065
2017-11-13 2017-09-30 13F COMFORT SYS USA COM 199908104 1,156,223 150,000 14.91 41,277 10.57 0.0050
2017-08-29 2017-06-30 13F/A-1 COMFORT SYS USA COM 199908104 1,006,223 966,323 2,421.86 37,331 2,453.42 0.0046
2017-08-11 2017-06-30 13F COMFORT SYS USA COM 199908104 1,006,223 966,323 37,331
2017-05-11 2017-03-31 13F COMFORT SYS USA COM 199908104 39,900 -29,460 -42.47 1,462 -36.71 0.0002
2017-02-10 2016-12-31 13F COMFORT SYS USA COM 199908104 69,360 23,990 52.88 2,310 73.68 0.0003
2016-11-14 2016-09-30 13F COMFORT SYS USA COM 199908104 45,370 45,370 1,330 0.0002
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.