William J. Sandbrook

Companies

• Andretti Acquisition Corp. IIChair Sep 5, 2024 to now¹
• Knife River CorpBoard member Jun 1, 2023 to now²
• Comfort Systems USABoard member Apr 12, 2018 to now³
• Zapata Quantum, Inc.Board member Jan 12, 2022 to Apr 1, 2024⁴
• Zapata Quantum, Inc.Officer Jan 12, 2022 to Jan 20, 2022⁴
• U.S. ConcreteBoard member Aug 23, 2011 to Mar 22, 2021⁵
• U.S. ConcreteChair May 29, 2018 to Apr 7, 2020⁶
• U.S. ConcreteChief executive officer Aug 23, 2011 to Apr 7, 2020⁵
• U.S. ConcretePresident Aug 23, 2011 to Mar 5, 2019⁵
• U.S. ConcreteVice chair Jan 2, 2018 to Apr 30, 2018⁷

Holdings

Stock this person has reported owning, from the forms officers and directors file with the SEC. See the biggest insider stakes.

Shares held

• Comfort Systems USA FIX7,941 shares⁸$11.8M at $1,481.27May 18, 2026
• ZQZapata Quantum, Inc. ZPTA1,618,567 shares⁹$849.7K at $0.53Jul 25, 2024
• KRKnife River Corp KNF7,735 shares¹⁰$386.4K at $49.95May 20, 2026

As of each latest filing. The line shows shares held over time.

Recent filings

• May 20, 2026Granted 2,040 shares of Knife River Corp¹⁰
• May 18, 2026Granted 105 shares of Comfort Systems USA⁸
• Apr 29, 2026Sold 1,500 shares at $1,732.67 of Comfort Systems USA¹¹
• Feb 24, 2026Sold 2,500 shares at $1,443.32 of Comfort Systems USA¹²
• Sep 10, 2025Sold 800 shares at $733.56 of Comfort Systems USA¹³
• Sep 9, 2025Sold 100 shares at $706.00 of Comfort Systems USA¹³
• Sep 9, 2025Sold 600 shares at $708.97 of Comfort Systems USA¹³
• Aug 25, 2025Sold 700 shares at $689.58 of Comfort Systems USA¹⁴
• May 22, 2025Granted 1,551 shares of Knife River Corp¹⁵
• May 16, 2025Granted 342 shares of Comfort Systems USA¹⁶
• May 17, 2024Granted 498 shares of Comfort Systems USA¹⁷
• May 15, 2024Granted 720 shares at $77.19 of Knife River Corp¹⁸
• May 15, 2024Granted 1,905 shares of Knife River Corp¹⁸
• Nov 15, 2023Granted 1,519 shares at $57.57 of Knife River Corp¹⁹
• Nov 9, 2023Sold 5,000 shares at $185.19 of Comfort Systems USA²⁰
• Sep 12, 2023Sold 7,500 shares at $187.52 of Comfort Systems USA²¹
• May 16, 2023Granted 1,065 shares of Comfort Systems USA²²
• Jun 2, 2022Gift 170 shares of Comfort Systems USA²³
• Jun 2, 2022Gift 170 shares of Comfort Systems USA²³
• Jun 2, 2022Gift 850 shares of Comfort Systems USA²³
• May 17, 2022Granted 1,869 shares of Comfort Systems USA²⁴