MarketPeel
Insider Trading Intelligence
WS

William J. Sandbrook

FIX
DIRECTOR · COMFORT SYSTEMS USA INC · CIK 0001527678
FILING MIX · LIFETIME57%/43%
BUYS
13
SELLS
10
TOTAL VALUE
$10.25M
COMPANIES
2
ACTIVE SINCE
May 2020
HOLDINGS NOW
15,506
AVG SELL PX
$540.38
TRADE KIND
SHOWING 23 / 23
Trades · vs SPY
Loading price series…
Performance · forward returns vs SPY
8 backtested trades · 8 horizons · 15 pending
Forward-return performance of every backtestable P/S trade by William J. Sandbrook, measured at 8 horizons from 7 days to 2 years. Deduped per economic event so co-filings count once. Excess return = trade return minus SPY return over the same window.
HORIZONTRADESWIN RATEINSIDER RETURNSPY RETURNMEAN EXCESSMEDIAN EXCESST-STAT
7d8+25.00%+4.35%+1.15%+3.20%+1.12%
14d8+25.00%+5.62%+1.23%+4.39%+3.23%
30d8+25.00%+6.61%+0.99%+5.24%+8.38%
60d8+0.00%+21.68%+3.94%+17.73%+19.36%
90d8(1 pending)+0.00%+28.67%+6.38%+22.99%+29.35%
180d8(2 pending)+0.00%+87.44%+9.24%+78.20%+83.80%
1y8(6 pending)+0.00%+113.80%+32.90%+80.90%+80.90%
2y8(6 pending)+0.00%+361.82%+54.34%+307.48%+307.48%
How to read this: Insider Returnis the average raw return of the filer's trades over the horizon. SPY Return is what SPY did over those same windows — reference only, not a comparison. The headline alpha number is Mean Excess = Insider − SPY; green means the filer beat SPY, red means they trailed it. Win rate is the share of individual trades where the filer beat SPY. T-statvalues above 2 mean the alpha is unlikely to be chance given the sample size. "Pending" counts trades where the horizon hasn't elapsed yet; their stats are not included in the row average.
Holdings over time
FIX · 7,771 shares · as of May 18, 2026
06,38212,76319,14525,526202120222023202420252026SHARES HELD
Trading cadence · quarterly flow
BUY SELL
2020
2020
2020
2021
2021
2021
2021
2022
2022
2022
2022
2023
2023
2023
2023
2024
2024
2024
2024
2025
2025
2025
2025
2026
2026
FLOW · 13 buys / 10 sellsCOVERAGE · 25 quarters
Form 4 filings · all activity
COMPANYTYPESHARESPRICEVALUEHELD AFTERTRADE DATEFILEDDETAILS
KNF
KNIFE RIVER CORP
PURCHASEGRANT
Stock grant
2,0407,735May 20, 2026May 21, 2026View →
FIX
COMFORT SYSTEMS USA INC
PURCHASEGRANT
Stock grant
1057,771May 18, 2026May 19, 2026View →
FIX
COMFORT SYSTEMS USA INC
SALE
1,500$1,732.67$2.60M7,666Apr 29, 2026Apr 30, 2026View →
FIX
COMFORT SYSTEMS USA INC
SALE
2,500$1,443.32$3.61M9,166Feb 24, 2026Feb 26, 2026View →
FIX
COMFORT SYSTEMS USA INC
SALE
800$733.56$586.8K11,666Sep 10, 2025Sep 10, 2025View →
FIX
COMFORT SYSTEMS USA INC
SALE
600$708.97$425.4K12,566Sep 9, 2025Sep 10, 2025View →
FIX
COMFORT SYSTEMS USA INC
SALE
100$706.00$70.6K12,466Sep 9, 2025Sep 10, 2025View →
FIX
COMFORT SYSTEMS USA INC
SALE
700$689.58$482.7K13,166Aug 25, 2025Aug 27, 2025View →
KNF
KNIFE RIVER CORP
PURCHASEGRANT
Stock grant
1,5515,695May 22, 2025May 27, 2025View →
FIX
COMFORT SYSTEMS USA INC
PURCHASEGRANT
Stock grant
34213,866May 16, 2025May 19, 2025View →
FIX
COMFORT SYSTEMS USA INC
PURCHASEGRANT
Stock grant
49813,524May 17, 2024May 20, 2024View →
KNF
KNIFE RIVER CORP
PURCHASEGRANT
Stock grant
720$77.19$55.6K4,144May 15, 2024May 16, 2024View →
KNF
KNIFE RIVER CORP
PURCHASEGRANT
Stock grant
1,9053,424May 15, 2024May 16, 2024View →
KNF
KNIFE RIVER CORP
PURCHASEGRANT
Stock grant
1,519$57.57$87.4K1,519Nov 15, 2023Nov 16, 2023View →
FIX
COMFORT SYSTEMS USA INC
SALE
5,000$185.19$925.9K13,026Nov 9, 2023Nov 9, 2023View →
FIX
COMFORT SYSTEMS USA INC
SALE
7,500$187.52$1.41M18,026Sep 12, 2023Sep 13, 2023View →
FIX
COMFORT SYSTEMS USA INC
PURCHASEGRANT
Stock grant
1,06525,526May 16, 2023May 17, 2023View →
FIX
COMFORT SYSTEMS USA INC
PURCHASEGRANT
Gift
170170Jun 2, 2022Jun 6, 2022View →
FIX
COMFORT SYSTEMS USA INC
SALEGRANT
Gift
17024,291Jun 2, 2022Jun 6, 2022View →
FIX
COMFORT SYSTEMS USA INC
SALEGRANT
Gift
85024,461Jun 2, 2022Jun 6, 2022View →
FIX
COMFORT SYSTEMS USA INC
PURCHASEGRANT
Stock grant
1,86925,311May 17, 2022May 19, 2022View →
FIX
COMFORT SYSTEMS USA INC
PURCHASEGRANT
Stock grant
1,93923,442May 18, 2021May 20, 2021View →
FIX
COMFORT SYSTEMS USA INC
PURCHASEGRANT
Stock grant
4,78821,503May 19, 2020May 21, 2020View →
Other insiders · FIX
Loading peer insiders…
About this filer
CIK 0001527678
ROLE
Director
PRIMARY
FIX
COMPANIES
2
ACTIVE SINCE
May 2020
MARKETPEEL · /INSIDER/0001527678DATA · SEC EDGAR · FORM 4 · CONSOLIDATED TAPE
FREE · DAILY · 6 AM ET

One short email. Insider buys, congressional trades, and plain-English analysis.

Feedback