SANDBROOK WILLIAM J

Director at Knife River Corp · on record since May 21, 2026
10% owner at Zapata Quantum, Inc. · on record since Apr 1, 2024
See Remarks at Zapata Quantum, Inc. · on record since Apr 1, 2024
Director at Andretti Acquisition Corp. II · on record since Sep 5, 2024
Executive Chairman at Andretti Acquisition Corp. II · on record since Sep 5, 2024
10% owner at Andretti Acquisition Corp. II · on record since Sep 5, 2024
Director at U.S. CONCRETE, INC. · on record since Aug 31, 2011
Director at COMFORT SYSTEMS USA INC · on record since Apr 30, 2026
Chairman and CEO at U.S. CONCRETE, INC. · on record since May 20, 2019
Director at Zapata Quantum, Inc. · on record since Jan 20, 2022
See Remarks at Zapata Quantum, Inc. · on record since Jan 20, 2022

Insider trading activity of SANDBROOK WILLIAM J

Transactions on record: 178; since Aug 24, 2011

Open-market buys: 11; $1.3M

Open-market sells: 77; $23.5M

Companies traded: 3; last filing May 21, 2026

Figures computed from official regulatory filings — .

Companies where SANDBROOK WILLIAM J has traded

Knife River Corp5 tx · $143K · May 21, 2026
COMFORT SYSTEMS USA INC22 tx · $10.6M · May 19, 2026
U.S. CONCRETE, INC.151 tx · $24.9M · Mar 22, 2021

Track record of SANDBROOK WILLIAM J

Statistical track record

Free account

Open-market buys: 11

Last buy: Feb 27, 2020

Win rates, median returns and the proven-insider analysis come with a free account.

Transaction history of SANDBROOK WILLIAM J

Co-insiders of SANDBROOK WILLIAM J

This page republishes public regulatory disclosures.

Company	Filed	Type	Qty	Price	Value · USD	Signals	Src
Knife River CorpListing on record	May 21, 2026	Award	2,040	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 19, 2026	Award	105	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	Apr 30, 2026	Sell	-1,500	1,732.67 USD	$2.6M	Unusual size	SEC
COMFORT SYSTEMS USA INCListing on record	Feb 26, 2026	Sell	-2,500	1,443.32 USD	$3.6M	Unusual size	SEC
COMFORT SYSTEMS USA INCListing on record	Sep 10, 2025	Sell	-100	706.00 USD	$70.6K		SEC
COMFORT SYSTEMS USA INCListing on record	Sep 10, 2025	Sell	-800	733.56 USD	$586.8K		SEC
COMFORT SYSTEMS USA INCListing on record	Sep 10, 2025	Sell	-600	708.97 USD	$425.4K		SEC
COMFORT SYSTEMS USA INCListing on record	Aug 27, 2025	Sell	-700	689.58 USD	$482.7K		SEC
Knife River CorpListing on record	May 27, 2025	Award	1,551	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 20, 2025	Award	342	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 21, 2024	Award	498	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Knife River CorpListing on record	May 16, 2024	Award	720	77.19 USD	$55.6K	Unusual size	SEC
Knife River CorpListing on record	May 16, 2024	Award	1,905	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Knife River CorpListing on record	Nov 16, 2023	Award	1,519	57.57 USD	$87.4K		SEC
COMFORT SYSTEMS USA INCListing on record	Nov 13, 2023	Sell	-5,000	185.19 USD	$926K	Unusual size	SEC
COMFORT SYSTEMS USA INCListing on record	Sep 14, 2023	Sell	-7,500	187.52 USD	$1.4M	Unusual size	SEC
COMFORT SYSTEMS USA INCListing on record	May 17, 2023	Award	1,065	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	Jun 6, 2022	Gift	-850	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	Jun 6, 2022	Gift	-170	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	Jun 6, 2022	Gift	170	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 19, 2022	Award	1,869	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 20, 2021	Award	1,939	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
U.S. CONCRETE, INC.Listing unverified	Mar 22, 2021	ExerciseD (derivative)	-11,720	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
U.S. CONCRETE, INC.Listing unverified	Mar 22, 2021	Exercise	11,720	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
U.S. CONCRETE, INC.Listing unverified	Mar 15, 2021	ExerciseD (derivative)	-11,720	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC

Company	Filed	Type	Qty	Price	Value · USD	Signals	Src
Knife River CorpListing on record	May 21, 2026	Award	2,040	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 19, 2026	Award	105	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	Apr 30, 2026	Sell	-1,500	1,732.67 USD	$2.6M	Unusual size	SEC
COMFORT SYSTEMS USA INCListing on record	Feb 26, 2026	Sell	-2,500	1,443.32 USD	$3.6M	Unusual size	SEC
COMFORT SYSTEMS USA INCListing on record	Sep 10, 2025	Sell	-100	706.00 USD	$70.6K		SEC
COMFORT SYSTEMS USA INCListing on record	Sep 10, 2025	Sell	-800	733.56 USD	$586.8K		SEC
COMFORT SYSTEMS USA INCListing on record	Sep 10, 2025	Sell	-600	708.97 USD	$425.4K		SEC
COMFORT SYSTEMS USA INCListing on record	Aug 27, 2025	Sell	-700	689.58 USD	$482.7K		SEC
Knife River CorpListing on record	May 27, 2025	Award	1,551	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 20, 2025	Award	342	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 21, 2024	Award	498	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Knife River CorpListing on record	May 16, 2024	Award	720	77.19 USD	$55.6K	Unusual size	SEC
Knife River CorpListing on record	May 16, 2024	Award	1,905	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
Knife River CorpListing on record	Nov 16, 2023	Award	1,519	57.57 USD	$87.4K		SEC
COMFORT SYSTEMS USA INCListing on record	Nov 13, 2023	Sell	-5,000	185.19 USD	$926K	Unusual size	SEC
COMFORT SYSTEMS USA INCListing on record	Sep 14, 2023	Sell	-7,500	187.52 USD	$1.4M	Unusual size	SEC
COMFORT SYSTEMS USA INCListing on record	May 17, 2023	Award	1,065	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	Jun 6, 2022	Gift	-850	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	Jun 6, 2022	Gift	-170	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	Jun 6, 2022	Gift	170	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 19, 2022	Award	1,869	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
COMFORT SYSTEMS USA INCListing on record	May 20, 2021	Award	1,939	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
U.S. CONCRETE, INC.Listing unverified	Mar 22, 2021	ExerciseD (derivative)	-11,720	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
U.S. CONCRETE, INC.Listing unverified	Mar 22, 2021	Exercise	11,720	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC
U.S. CONCRETE, INC.Listing unverified	Mar 15, 2021	ExerciseD (derivative)	-11,720	0.00 USD	n/a (Non-cash transaction: the filing states a price of zero (award, gift, exercise))		SEC