Comfort Systems USA, Inc.
MX ˙ BMV ˙ US1999081045
SecurityMX:FIX / Comfort Systems USA, Inc.
InstitutionDriehaus Capital Management Llc
Latest Disclosed Ownership41,105 shares
Latest Disclosed Value $ 56,683,384
Driehaus Capital Management Llc reports 1.54% increase in ownership of FIX / Comfort Systems USA, Inc.

On May 15, 2026 - Driehaus Capital Management Llc filed a 13F-HR form disclosing ownership of 41,105 shares of Comfort Systems USA, Inc. (MX:FIX) valued at $56,683,384 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 40,482 shares of Comfort Systems USA, Inc.. This represents a change in shares of 1.54% 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)
2026-05-15 2026-03-31 13F Comfort Systems USA COM 199908104 41,105 623 1.54 56,683 50.03 0.4152
2026-02-17 2025-12-31 13F Comfort Systems USA COM 199908104 40,482 -10,112 -19.99 37,781 -9.50 0.2566
2025-11-14 2025-09-30 13F COMFORT SYSTEMS USA COM 199908104 50,594 -3,743 -6.89 41,749 43.29 0.2990
2025-08-14 2025-06-30 13F COMFORT SYSTEMS USA COM 199908104 54,337 54,337 29,136 0.2331
2025-05-15 2025-03-31 13F COMFORT SYSTEMS USA COM 199908104 0 -159,010 -100.00 0 -100.00
2025-02-14 2024-12-31 13F COMFORT SYSTEMS USA COM 199908104 159,010 -45,627 -22.30 67,430 -15.59 0.5565
2024-11-14 2024-09-30 13F COMFORT SYSTEMS USA COM 199908104 204,637 51,934 34.01 79,880 72.01 0.6858
2024-08-15 2024-06-30 13F/A-1 COMFORT SYSTEMS USA COM 199908104 152,703 8,363 5.79 46,440 1.27 0.4493
2024-08-14 2024-06-30 13F COMFORT SYSTEMS USA COM 199908104 152,703 8,363 46,440 0.4477
2024-05-15 2024-03-31 13F COMFORT SYSTEMS USA COM 199908104 144,340 -48,641 -25.21 45,858 15.54 0.4568
2024-02-14 2023-12-31 13F COMFORT SYSTEMS USA COM 199908104 192,981 -35,498 -15.54 39,690 1.94 0.4782
2023-11-14 2023-09-30 13F COMFORT SYSTEMS USA COM 199908104 228,479 -27,456 -10.73 38,935 -7.35 0.5061
2023-08-14 2023-06-30 13F COMFORT SYSTEMS USA COM 199908104 255,935 4,474 1.78 42,025 14.50 0.5306
2023-05-15 2023-03-31 13F COMFORT SYSTEMS USA COM 199908104 251,461 4,476 1.81 36,703 29.13 0.5151
2023-02-14 2022-12-31 13F COMFORT SYSTEMS USA COM 199908104 246,985 45,313 22.47 28,423 44.80 0.4238
2022-11-14 2022-09-30 13F COMFORT SYSTEMS USA COM 199908104 201,672 201,672 19,629 0.2972
2019-08-14 2019-06-30 13F COMFORT SYSTEMS USA COM 199908104 0 -79,795 -100.00 0 -100.00
2019-05-15 2019-03-31 13F COMFORT SYSTEMS USA COM 199908104 79,795 -105,571 -56.95 4,180 -48.38 0.1569
2019-02-14 2018-12-31 13F COMFORT SYSTEMS USA COM 199908104 185,366 54,808 41.98 8,097 9.97 0.3464
2018-11-14 2018-09-30 13F COMFORT SYSTEMS USA COM 199908104 130,558 130,558 7,363 0.2266
2016-11-14 2016-09-30 13F COMFORT SYSTEMS USA COM 199908104 0 -82,103 -100.00 0 -100.00
2016-08-15 2016-06-30 13F COMFORT SYSTEMS USA COM 199908104 82,103 -42,548 -34.13 2,674 -32.47 0.0954
2016-05-13 2016-03-31 13F COMFORT SYSTEMS USA COM 199908104 124,651 -58,504 -31.94 3,960 -23.92 0.1284
2016-02-12 2015-12-31 13F COMFORT SYSTEMS USA COM 199908104 183,155 54,402 42.25 5,205 48.29 0.1755
2015-11-16 2015-09-30 13F COMFORT SYSTEMS USA COM 199908104 128,753 128,753 0.00 3,510 0.1266
2015-08-14 2015-06-30 13F COMFORT SYSTEMS USA COM 199908104 0 -148,271 -100.00 0 -100.00
2015-05-15 2015-03-31 13F COMFORT SYSTEMS USA COM 199908104 148,271 56,000 60.69 3,120 97.47 0.1081
2015-02-13 2014-12-31 13F COMFORT SYSTEMS USA COM 199908104 92,271 92,271 1,580 0.0636
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.