Mark Steven Bender

CIK 1330417 · EVP & CFO · last filed 2026-05-14

Mark Steven Bender is an EVP & CFO who has filed 112 SEC Form 4 insider transactions across 2 companies since 2007. The most recent filing, for WLK, was dated May 14, 2026. Across all open-market trades the lifetime net is −$36.4M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $2.9M across reported positions.

"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.

Disclosed Exposure

$2.90M

Companies

2

Total Filings

112

Lifetime Open-Market Net

-$36.41M

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
WLK	EVP & CFO	35,895	$72.16	$2.59M	-$36.73M	102	2026-05-14
WLKP	SVP, CFO	14,000	$22.03	$308.4K	$317.5K	3	2020-03-16

Recent Filings

112 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
2026-05-14	WLK	Mixed	+7,880	-$514.3K	EDGAR
2026-03-30	WLK	Sell (S)	−16,413	-$1.85M	EDGAR
2026-03-27	WLK	Notice (144)	−16,413	-$1.85M	EDGAR
2026-03-06	WLK	Tax (F)	−1,171	-$122.9K	EDGAR
2026-03-02	WLK	Mixed	−17,409	-$2.03M	EDGAR
2026-02-27	WLK	Notice (144)	−30,102	-$3.00M	EDGAR
2026-02-23	WLK	Mixed	+1,332	-$41.9K	EDGAR
2026-02-19	WLK	Mixed	+3,542	-$119.6K	EDGAR
2025-02-24	WLK	Mixed	+5,289	-$390.2K	EDGAR
2025-02-20	WLK	Mixed	+9,541	-$495.8K	EDGAR

Showing 1–10 of 112

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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.