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WILLIAM J SANDBROOK

CIK 1527678 · See Remarks · last filed 2026-05-21

WILLIAM J SANDBROOK is a corporate insider who has filed 104 SEC Form 4 insider transactions across 3 companies since 2018. The most recent filing, for KNF, was dated May 21, 2026. Across all open-market trades the lifetime net is −$9.6M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $13.6M across reported positions. 4 SEC filings were submitted jointly with MICHAEL ANDRETTI.

"Disclosed insider exposure" sums this person's most-recently-reported share counts across each company they're an insider in, multiplied by the current underlying price. It is not net worth — it misses retail holdings, private investments, real estate, index funds, and any company where the person isn't an SEC-reporting insider. For informational purposes only.

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Disclosed Exposure

$13.59M

Companies

3

Total Filings

104

Lifetime Open-Market Net

-$9.64M

Filer Profile

Reported Address
C/O COMFORT SYSTEMS USA, INC.
9753 KATY FREEWAY, SUITE 700
HOUSTON, TX 77024
Related Filers
MICHAEL ANDRETTI — 4 joint filings, latest 2024-09-05
William Matthew Brown — 4 joint filings, latest 2024-09-05
Andretti Sponsor LLC — 3 joint filings, latest 2024-04-01
Mario Andretti — 1 joint filings, latest 2024-09-05
Profile details as reported on the filer's SEC submissions — for individual insiders the address is often in care of the issuer. Related filers are identified from jointly filed SEC submissions and shared reported addresses. View filings on SEC EDGAR.

Holdings By Company

Latest on-record share count from this person's most recent non-derivative Form 4 transaction in each company. Disclosed exposure = shares × current underlying price.
Symbol Role Shares Price Disclosed Exposure Lifetime OM Net Filings Latest Filed
KNF Director 7,735 $54.38 $420.6K $0 4 2026-05-21
FIX Director 7,941 $1658.43 $13.17M -$9.64M 17 2026-05-19
Zapata Quantum, Inc. (WNNR.U) Delisted See Remarks — $14.00 — $0 1 2022-01-20

Recent Filings

104 filings
Insider activity across all companies, newest first. Form 4 rows are post-trade confirmations (buys, sells, grants, exercises). Notice (144) rows are pre-trade notices of intent to sell restricted or control stock under Rule 144 — they may not all execute. Compare adjacent dates to see which notices became actual sales.
Filed Symbol Action Net Shares Net $ Link
2026-05-21 KNF Grant (A) +2,040 $0 EDGAR
2026-05-19 FIX Grant (A) +105 $0 EDGAR
2026-04-30 FIX Sell (S) −1,500 -$2.60M EDGAR
2026-04-29 FIX Notice (144) −1,500 -$2.60M EDGAR
2026-02-26 FIX Sell (S) −2,500 -$3.61M EDGAR
2026-02-24 FIX Notice (144) −2,500 -$3.61M EDGAR
2025-09-10 FIX Sell (S) −1,500 -$1.08M EDGAR
2025-09-10 FIX Notice (144) −800 -$586.8K EDGAR
2025-09-09 FIX Notice (144) −700 -$496.0K EDGAR
2025-08-27 FIX Sell (S) −700 -$482.7K EDGAR
Showing 1–10 of 104
Page 1 of 11
Form 4 codes: P = open-market purchase · S = open-market sale · A = grant/award · M = option exercise · F = tax withholding at vest · G = bona-fide gift · D = disposition to issuer · J = other (see filing footnote). Only P / S codes carry directional signal.
Notice (144 / 144/A): Form 144 is a notice of intent to sell restricted/control stock under Rule 144, filed before the sale; 144/A is an amendment. Many notices are pre-scheduled under Rule 10b5-1 plans. A Form 4 with code S typically follows within a few days when the planned sale executes; missing follow-up Form 4s suggest the notice was cancelled or modified.