Comfort Systems USA, Inc.
MX ˙ BMV ˙ US1999081045
SecurityMX:FIX / Comfort Systems USA, Inc.
InstitutionTwo Sigma Investments, Lp
ManagerJohn Overdeck, David Siegel
Latest Disclosed Ownership8,394 shares
Latest Disclosed Value $ 11,575,242
Two Sigma Investments, Lp ownership in FIX / Comfort Systems USA, Inc.

On May 15, 2026 - Two Sigma Investments, Lp filed a 13F-HR form disclosing ownership of 8,394 shares of Comfort Systems USA, Inc. (MX:FIX) valued at $11,575,242 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 3,579 shares of Comfort Systems USA, Inc.. This represents a change in shares of 134.53% during the quarter.

Two Sigma Investments, Lp has a history of taking positions in derivatives of the underlying security (FIX) in the form of stock options. The firm currently holds call options representing 2,000 of underlying shares valued at $2,757,980 USD and put options representing 2,000 of underlying shares valued at $2,757,980 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:FIX / Comfort Systems USA, Inc. Historical Put/Call Ratio
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 8,394 4,815 134.53 11,575 246.56 0.0093
2026-02-17 2025-12-31 13F COMFORT SYS USA COM 199908104 3,579 -27 -0.75 3,340 12.27 0.0047
2025-11-14 2025-09-30 13F COMFORT SYS USA COM 199908104 3,606 -14,316 -79.88 2,976 -69.04 0.0044
2025-08-14 2025-06-30 13F COMFORT SYS USA COM 199908104 17,922 -165,129 -90.21 9,610 -83.71 0.0170
2025-05-15 2025-03-31 13F COMFORT SYS USA COM 199908104 183,051 142,183 347.91 59,003 240.46 0.1261
2025-02-14 2024-12-31 13F COMFORT SYS USA COM 199908104 40,868 3,193 8.48 17,330 17.84 0.0378
2024-11-14 2024-09-30 13F COMFORT SYS USA COM 199908104 37,675 -15,270 -28.84 14,706 -8.66 0.0322
2024-08-14 2024-06-30 13F COMFORT SYS USA COM 199908104 52,945 49,353 1,373.97 16,102 1,311.13 0.0367
2024-05-15 2024-03-31 13F COMFORT SYS USA COM 199908104 3,592 -7,808 -68.49 1,141 -51.32 0.0027
2024-02-14 2023-12-31 13F COMFORT SYS USA COM 199908104 11,400 0 0.00 2,345 20.70 0.0054
2023-11-14 2023-09-30 13F COMFORT SYS USA COM 199908104 11,400 -6,805 -37.38 1,943 -35.03 0.0052
2023-08-14 2023-06-30 13F COMFORT SYS USA COM 199908104 18,205 -20,809 -53.34 2,989 -47.51 0.0075
2023-05-15 2023-03-31 13F COMFORT SYS USA COM 199908104 39,014 24,764 173.78 5,694 247.41 0.0163
2023-02-14 2022-12-31 13F COMFORT SYS USA COM 199908104 14,250 8,260 137.90 1,640 181.13 0.0051
2022-11-14 2022-09-30 13F COMFORT SYS USA COM 199908104 5,990 5,990 583 0.0020
2020-11-16 2020-09-30 13F COMFORT SYS USA COM 199908104 0 -9,078 -100.00 0 -100.00
2020-08-14 2020-06-30 13F COMFORT SYS USA COM 199908104 9,078 9,078 370 0.0018
2020-05-15 2020-03-31 13F COMFORT SYS USA COM 199908104 0 -6,167 -100.00 0 -100.00
2020-02-14 2019-12-31 13F COMFORT SYS USA COM 199908104 6,167 6,167 307 0.0009
2019-08-14 2019-06-30 13F COMFORT SYS USA COM 199908104 0 -141,429 -100.00 0 -100.00
2019-05-15 2019-03-31 13F COMFORT SYS USA COM 199908104 141,429 -39,887 -22.00 7,409 -6.45 0.0240
2019-02-14 2018-12-31 13F COMFORT SYS USA COM 199908104 181,316 77,479 74.62 7,920 35.25 0.0310
2018-11-14 2018-09-30 13F COMFORT SYS USA COM 199908104 103,837 68,196 191.34 5,856 258.82 0.0160
2018-08-14 2018-06-30 13F COMFORT SYS USA COM 199908104 35,641 28,328 387.36 1,632 440.40 0.0049
2018-05-15 2018-03-31 13F COMFORT SYS USA COM 199908104 7,313 7,313 302 0.0010
2017-11-14 2017-09-30 13F COMFORT SYS USA COM 199908104 0 -7,200 -100.00 0 -100.00
2017-08-14 2017-06-30 13F COMFORT SYS USA COM 199908104 7,200 -138,539 -95.06 267 -95.00 0.0010
2017-05-15 2017-03-31 13F COMFORT SYS USA COM 199908104 145,739 -17,091 -10.50 5,341 -1.49 0.0180
2017-02-14 2016-12-31 13F COMFORT SYS USA COM 199908104 162,830 110,058 208.55 5,422 250.48 0.0208
2016-11-14 2016-09-30 13F COMFORT SYS USA COM 199908104 52,772 43,244 453.86 1,547 399.03 0.0056
2016-08-15 2016-06-30 13F COMFORT SYS USA COM 199908104 9,528 -143,152 -93.76 310 -93.61 0.0013
2016-05-16 2016-03-31 13F COMFORT SYS USA COM 199908104 152,680 -121,970 -44.41 4,851 -37.86 0.0231
2016-02-16 2015-12-31 13F COMFORT SYS USA COM 199908104 274,650 -43,096 -13.56 7,806 -9.88 0.0374
2015-11-16 2015-09-30 13F COMFORT SYS USA COM 199908104 317,746 114,413 56.27 8,662 85.64 0.0444
2016-02-09 2015-06-30 13F/A-1 COMFORT SYS USA COM 199908104 203,333 96,881 91.01 4,666 108.30 0.0227
2015-08-14 2015-06-30 13F COMFORT SYS USA COM 199908104 203,333 4,666
2016-02-09 2015-03-31 13F/A-1 COMFORT SYS USA COM 199908104 106,452 39,637 59.32 2,240 95.80 0.0110
2015-05-15 2015-03-31 13F COMFORT SYS USA COM 199908104 106,452 2,239
2016-02-09 2014-12-31 13F/A-1 COMFORT SYS USA COM 199908104 66,815 -24,495 -26.83 1,144 -7.52 0.0066
2015-02-17 2014-12-31 13F COMFORT SYS USA COM 199908104 66,815 1,144
2016-02-09 2014-09-30 13F/A-1 COMFORT SYS USA COM 199908104 91,310 -7,020 -7.14 1,237 -20.40 0.0058
2014-11-14 2014-09-30 13F COMFORT SYS USA COM 199908104 91,310 1,237
2016-02-09 2014-06-30 13F/A-1 COMFORT SYS USA COM 199908104 98,330 -36,053 -26.83 1,554 -24.12 0.0073
2014-08-14 2014-06-30 13F COMFORT SYS USA COM 199908104 98,330 1,553
2014-05-15 2014-03-31 13F COMFORT SYS USA COM 199908104 134,383 -71,075 -34.59 2,048 -48.59 0.0110
2014-02-14 2013-12-31 13F COMFORT SYS USA COM 199908104 205,458 136,277 196.99 3,984 242.56 0.0220
2013-11-14 2013-09-30 13F COMFORT SYS USA COM 199908104 69,181 49,336 248.61 1,163 292.91 0.0074
2013-08-14 2013-06-30 13F COMFORT SYS USA COM 199908104 19,845 19,845 296 0.0021
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F COMFORT SYS USA COM Call 2,000 2,758 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F COMFORT SYS USA COM Put 2,000 2,758 n/a n/a n/a
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.