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THOMAS J SEIFERT

CIK 1473289 · Chief Financial Officer · last filed 2026-09-15

THOMAS J SEIFERT is a Chief Financial Officer who has filed 269 SEC Form 4 insider transactions across 4 companies since 2009. The most recent filing, for NET, was dated Sep 17, 2026. Across all open-market trades the lifetime net is −$314.0M, making them a net seller over the disclosed history. Current disclosed insider exposure totals $180.2M across reported positions. 13 SEC filings were submitted jointly with ADVANCED MICRO DEVICES INC.

"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

$180.25M

Companies

4

Total Filings

269

Lifetime Open-Market Net

-$313.97M

Filer Profile

Reported Address
101 TOWNSEND STREET
SAN FRANCISCO, CA 94107
Related Filers
ADVANCED MICRO DEVICES INC — 13 joint filings, latest 2012-06-19
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
NET Chief Financial Officer 200,239 $351.67 $70.42M -$310.49M 153 2026-09-15
WOLF Director 20,476 $27.71 $567.4K $0 2 2025-02-03
IPGP Director 8,946 $77.75 $695.6K -$3.48M 13 2022-05-25
AMD SVP, CFO 176,383 $615.52 $108.57M $0 12 2012-06-19

Recent Filings

269 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
2026-09-17 NET Notice (144) −10,000 -$3.25M EDGAR
2026-09-15 NET Tax (F) −2,944 -$963.4K EDGAR
2026-08-19 NET Mixed — -$3.07M EDGAR
2026-08-18 NET Tax (F) −2,944 -$929.7K EDGAR
2026-08-17 NET Notice (144) −10,000 -$3.16M EDGAR
2026-08-06 NET Mixed — -$14.06M EDGAR
2026-08-06 NET Mixed — -$14.06M EDGAR
2026-08-04 NET Notice (144) −55,000 -$15.55M EDGAR
2026-07-17 NET Notice (144) −10,000 -$2.72M EDGAR
2026-07-17 NET Mixed −2,943 -$3.60M EDGAR
Showing 1–10 of 269
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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.