MARK A MCCOLLUM

CIK 1215888 · President and CEO · last filed 2026-06-05

"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

$4.44M

Companies

9

Total Filings

87

Lifetime Open-Market Net

-$11.99M

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
SDRL Director 7,269 $44.25 $321.7K $0 4 2026-06-05
OKE Director 2,572 $90.59 $233.0K $0 2 2026-05-22
WLK Director 9,656 $88.50 $854.6K $0 11 2025-08-11
MARATHON OIL CORP (MRO) Delisted Director 0 $28.55 $0 $0 4 2024-11-22
Weatherford International plc (WFT) Delisted President and CEO 1,665,615 $0 5 2019-04-25
AROC Director 82,751 $36.61 $3.03M $0 4 2018-04-27
HALLIBURTON CO (HALw) Delisted EVP - Chief Financial Officer 204,993 -$11.99M 45 2017-03-01
Archrock, Inc. (EXH) Delisted Director 39,195 $0 7 2015-03-05
Archrock Partners, L.P. (EXLP) Delisted Director 2,000 $0 4 2009-06-01

Recent Filings · Page 2 of 9

87 filings
Form 4 transactions across all companies, newest first.
Filed Symbol Action Net Shares Net $ Link
2023-08-14 WLK Mixed +1,446 $0 EDGAR
2023-03-03 MARATHON OIL CORP (MRO) Delisted Grant (A) +7,754 $0 EDGAR
2022-12-02 MARATHON OIL CORP (MRO) Delisted Grant (A) +415 $0 EDGAR
2022-08-15 WLK Mixed +1,763 $0 EDGAR
2022-03-04 WLK Gift (G) −3,000 $0 EDGAR
2021-08-16 WLK Mixed +2,400 $0 EDGAR
2020-08-17 WLK Mixed +2,387 $0 EDGAR
2019-12-17 Mixed −1,663,874 $13.2K
2019-08-19 WLK Mixed +1,409 $0 EDGAR
2019-05-20 WLK Exer (M) +987 $0 EDGAR
Showing 1120 of 87
Page 2 of 9
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.