Comfort Systems USA, Inc.
MX ˙ BMV ˙ US1999081045
SecurityMX:FIX / Comfort Systems USA, Inc.
InstitutionBlackRock, Inc.
Latest Disclosed Ownership2,917,000 shares
Ownership 8.30%
BlackRock, Inc. ownership in FIX / Comfort Systems USA, Inc.

2026-01-21 - BlackRock, Inc. has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 2,917,000 shares of Comfort Systems USA, Inc. (MX:FIX). This represents 8.3 percent ownership of the company. In their previous filing dated 2025-12-04 , BlackRock, Inc. had reported owning 3,803,901 shares, indicating a decrease of -23.32 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)
2026-01-21 2026-01-21 13G/A 3,803,901 2,917,000 -23.32 8.30 -23.15
2025-12-04 2025-12-04 13G/A 3,349,547 3,803,901 13.56 10.80 14.89
2025-04-24 2025-04-24 13G/A 4,807,189 3,349,547 -30.32 9.40 -30.37
2024-01-23 2024-01-23 13G/A 5,880,679 4,807,189 -18.25 13.50 -17.68
2023-01-26 2023-01-26 13G/A 5,880,679 5,880,679 0.00 16.40 0.00
2023-01-20 2023-01-20 13G 5,487,085 5,880,679 7.17 16.40 7.89
2022-01-27 2022-01-27 13G/A 5,487,085 5,487,085 0.00 15.20 0.00
2022-01-26 2022-01-26 13G/A 5,445,294 5,487,085 0.77 15.20 1.33
2021-01-26 2021-01-26 13G/A 6,466,910 5,445,294 -15.80 15.00 -14.77
2020-02-04 2020-02-04 13G/A 6,363,074 6,466,910 1.63 17.60 2.92
2019-01-24 2019-01-24 13G/A 5,285,746 6,363,074 20.38 17.10 20.42
2018-01-19 2018-01-19 13G/A 4,739,804 5,285,746 11.52 14.20 11.81
2017-01-12 2017-01-12 13G/A 4,317,603 4,739,804 9.78 12.70 10.43
2016-01-08 2016-01-08 13G/A 4,166,495 4,317,603 3.63 11.50 3.60
2015-10-09 2015-10-09 13G/A 4,166,495 11.10
2015-01-15 2015-01-15 13G/A 3,370,716 9.00
2014-04-08 2014-04-08 13G/A 3,772,029 10.00
2014-01-28 2014-01-28 13G/A 3,462,594 9.30
2013-02-08 2013-02-08 13G/A 2,973,653 7.98
2012-02-13 2012-02-13 13G/A 2,929,789 7.82

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)
2026-05-13 2026-03-31 13F COMFORT SYS USA COM 199908104 3,512,927 64,292 1.86 4,844,291 50.51 0.0846
2026-02-12 2025-12-31 13F COMFORT SYS USA COM 199908104 3,448,635 -528,953 -13.30 3,218,576 -1.94 0.0544
2025-11-12 2025-09-30 13F COMFORT SYS USA COM 199908104 3,977,588 96,388 2.48 3,282,226 57.71 0.0575
2025-08-12 2025-06-30 13F COMFORT SYS USA COM 199908104 3,881,200 -71,740 -1.81 2,081,138 63.34 0.0396
2025-05-02 2025-03-31 13F COMFORT SYS USA COM 199908104 3,952,940 -958,796 -19.52 1,274,151 -38.83 0.0268
2025-02-07 2024-12-31 13F COMFORT SYS USA COM 199908104 4,911,736 -61,440 -1.24 2,082,871 7.29 0.0421
2024-11-13 2024-09-30 13F COMFORT SYS USA COM 199908104 4,973,176 353,795 7.66 1,941,279 38.18 0.0408
2024-08-13 2024-06-30 13F COMFORT SYS USA COM 199908104 4,619,381 137,163 3.06 1,404,846 -1.35 0.0318
2024-05-10 2024-03-31 13F COMFORT SYS USA COM 199908104 4,482,218 -324,971 -6.76 1,424,045 44.03 0.0332
2024-02-13 2023-12-31 13F COMFORT SYS USA COM 199908104 4,807,189 -1,292,202 -21.19 988,695 -4.88 0.0252
2023-11-13 2023-09-30 13F COMFORT SYS USA COM 199908104 6,099,391 -120,976 -1.94 1,039,397 1.76 0.0299
2023-08-11 2023-06-30 13F COMFORT SYS USA COM 199908104 6,220,367 203,566 3.38 1,021,384 16.30 0.0282
2023-05-12 2023-03-31 13F COMFORT SYS USA COM 199908104 6,016,801 136,122 2.31 878,212 29.77 0.0259
2023-02-13 2022-12-31 13F COMFORT SYS USA COM 199908104 5,880,679 338,321 6.10 676,749 25.45 0.0212
2022-11-14 2022-09-30 13F COMFORT SYS USA COM 199908104 5,542,358 32,236 0.59 539,438 17.74 0.0183
2022-08-12 2022-06-30 13F COMFORT SYS USA COM 199908104 5,510,122 15,384 0.28 458,167 -6.32 0.0147
2022-05-12 2022-03-31 13F COMFORT SYS USA COM 199908104 5,494,738 7,653 0.14 489,087 -9.91 0.0132
2022-02-10 2021-12-31 13F COMFORT SYS USA COM 199908104 5,487,085 102,801 1.91 542,893 41.38 0.0138
2021-11-09 2021-09-30 13F COMFORT SYS USA COM 199908104 5,384,284 -44,425 -0.82 384,009 -10.22 0.0108
2021-08-11 2021-06-30 13F COMFORT SYS USA COM 199908104 5,428,709 -263,816 -4.63 427,727 0.49 0.0119
2021-05-07 2021-03-31 13F COMFORT SYS USA COM 199908104 5,692,525 247,231 4.54 425,630 48.43 0.0125
2021-02-05 2020-12-31 13F COMFORT SYS USA COM 199908104 5,445,294 -287,512 -5.02 286,749 -2.89 0.0091
2020-11-06 2020-09-30 13F COMFORT SYS USA COM 199908104 5,732,806 -495,379 -7.95 295,295 16.35 0.0109
2020-08-14 2020-06-30 13F COMFORT SYS USA COM 199908104 6,228,185 -316,552 -4.84 253,800 6.10 0.0101
2020-05-01 2020-03-31 13F COMFORT SYS USA COM 199908104 6,544,737 77,827 1.20 239,210 -25.80 0.0117
2020-02-13 2019-12-31 13F COMFORT SYS USA COM 199908104 6,466,910 -66,036 -1.01 322,376 11.57 0.0124
2019-11-08 2019-09-30 13F COMFORT SYS USA COM 199908104 6,532,946 76,556 1.19 288,953 -12.23 0.0121
2019-08-22 2019-06-30 13F/A-1 COMFORT SYS USA COM 199908104 6,456,390 244,286 3.93 329,209 1.15 0.0141
2019-08-13 2019-06-30 13F COMFORT SYS USA COM 199908104 6,456,390 244,286 329,209
2019-05-09 2019-03-31 13F COMFORT SYS USA COM 199908104 6,212,104 -150,970 -2.37 325,451 17.09 0.0145
2019-02-08 2018-12-31 13F COMFORT SYS USA COM 199908104 6,363,074 -112,071 -1.73 277,939 -23.89 0.0140
2018-11-09 2018-09-30 13F COMFORT SYS USA COM 199908104 6,475,145 343,379 5.60 365,197 30.04 0.0158
2018-08-09 2018-06-30 13F COMFORT SYS USA COM 199908104 6,131,766 643,685 11.73 280,835 24.05 0.0129
2018-05-09 2018-03-31 13F COMFORT SYS USA COM 199908104 5,488,081 202,335 3.83 226,383 -1.88 0.0108
2018-02-09 2017-12-31 13F COMFORT SYS USA COM 199908104 5,285,746 213,140 4.20 230,723 27.41 0.0110
2017-11-14 2017-09-30 13F COMFORT SYS USA COM 199908104 5,072,606 92,421 1.86 181,091 -1.99 0.0091
2017-08-10 2017-06-30 13F COMFORT SYS USA COM 199908104 4,980,185 -87,710 -1.73 184,766 -0.52 0.0098
2017-05-12 2017-03-31 13F COMFORT SYS USA COM 199908104 5,067,895 5,059,889 63,201.21 185,736 69,725.56 0.0102
2017-02-10 2016-12-31 13F COMFORT SYS USA COM 199908104 8,006 -14,584 -64.56 266 -59.82 0.0004
2016-11-08 2016-09-30 13F COMFORT SYS USA COM 199908104 22,590 5,890 35.27 662 21.69 0.0010
2016-08-10 2016-06-30 13F COMFORT SYS USA COM 199908104 16,700 14,026 524.53 544 540.00 0.0008
2016-05-10 2016-03-31 13F COMFORT SYS USA COM 199908104 2,674 1,403 110.39 85 136.11 0.0001
2016-02-11 2015-12-31 13F COMFORT SYS USA COM 199908104 1,271 -2,171 -63.07 36 -61.70 0.0001
2015-11-13 2015-09-30 13F COMFORT SYS USA COM 199908104 3,442 2,077 152.16 94 193.75 0.0001
2015-08-07 2015-06-30 13F COMFORT SYS USA COM 199908104 1,365 0 0.00 32 10.34 0.0000
2015-05-13 2015-03-31 13F COMFORT SYS USA COM 199908104 1,365 0 0.00 29 20.83 0.0000
2015-02-09 2014-12-31 13F COMFORT SYS USA COM 199908104 1,365 0 0.00 24 26.32 0.0000
2014-10-29 2014-09-30 13F COMFORT SYS USA COM 199908104 1,365 0 0.00 19 -13.64 0.0000
2014-08-06 2014-06-30 13F COMFORT SYS USA COM 199908104 1,365 -100 -6.83 22 -4.35 0.0000
2014-05-02 2014-03-31 13F COMFORT SYS USA COM 199908104 1,465 0 0.00 23 -20.69 0.0000
2014-02-12 2013-12-31 13F COMFORT SYS USA COM 199908104 1,465 -94 -6.03 29 7.41 0.0000
2013-11-12 2013-09-30 13F COMFORT SYS USA COM 199908104 1,559 0 0.00 27 12.50 0.0001
2013-08-13 2013-06-30 13F COMFORT SYS USA COM 199908104 1,559 1,559 24 0.0000
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.