Mark A. Schallenberger

CIK 1960742 · Chief Operating Officer · last filed 2026-08-18

Mark A. Schallenberger is a Chief Operating Officer who has filed 7 SEC Form 4 insider transactions across 1 company since 2023. The most recent filing, for XTNT, was dated Aug 18, 2026. Current disclosed insider exposure totals $384.9K 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

$384.9K

Companies

1

Total Filings

7

Lifetime Open-Market Net

$0

Filer Profile

Reported Address

C/O XTANT MEDICAL HOLDINGS, INC.
664 CRUISER LANE
BELGRADE, MT 59714

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
XTNT	Chief Operating Officer	1,113,157	$0.35	$384.9K	$0	7	2026-08-18

Recent Filings

7 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
2026-08-18	XTNT	Mixed	+442,930	-$2.2K	EDGAR
2026-02-18	XTNT	Tax (F)	−7,709	-$4.5K	EDGAR
2025-11-18	XTNT	Grant (A)	+292,253	$0	EDGAR
2025-01-17	XTNT	Grant (A)	+173,469	$0	EDGAR
2024-04-05	XTNT	Grant (A)	+177,551	$0	EDGAR
2023-08-17	XTNT	Grant (A)	+116,144	$0	EDGAR
2023-02-17	XTNT	Grant (A)	+89,000	$0	EDGAR

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.