Sebastian Siemiatkowski

CIK 2097107 · Chief Executive Officer · last filed 2026-08-28

Sebastian Siemiatkowski is a Chief Executive Officer who has filed 2 SEC Form 4 insider transactions across 1 company since 2026. The most recent filing shows the insider bought $9.9M of KLAR on Aug 28, 2026. Across all open-market trades the lifetime net is +$9.9M, making them a net buyer over the disclosed history. Current disclosed insider exposure totals $365.2M 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

$365.21M

Companies

1

Total Filings

2

Lifetime Open-Market Net

$9.95M

Filer Profile

Reported Address

10 YORK ROAD
LONDON SE1 7ND

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
KLAR	Chief Executive Officer	25,344,322	$14.41	$365.21M	$9.95M	2	2026-08-28

Recent Filings

2 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
2026-08-28	KLAR	Buy (P)	+692,506	$9.95M	EDGAR
2026-04-15	KLAR	Grant (A)	—	$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.