Thomas J. Seifert
Thomas J. Seifert: Chief Financial Officer at Cloudflare. What Thomas J. Seifert holds in an AI or semiconductor company tracked on Silicon Floor, from their SEC filings, broken down: the shares held and how, then any restricted shares, options or other rights declared.
Cloudflare (NET)
Thomas J. Seifert holds 497,464 Cloudflare shares (0.14% of the company), worth about $180.1M at the last price, according to the Form 4 of Sep 17, 2026.
- Shares held: 380,637 (0.11%), $137.8M — Held through companies or funds (See footnote): 288,300 Class B, 92,337 Class A.
- Shares held: 116,827 (0.03%), $42.3M — Held in their own name: 107,902 Class A, 8,925 Class B.
- Options: 500,000 (0.14%), $181.0M — The right to buy 500,000 shares at $44.72 each, until 2032. Not bought yet.
Declarations
- Cloudflare (NET) — Form 4 of Sep 17, 2026 (Chief Financial Officer): conversion of 10,000; open-market sale of 100 at $318.90; 497,464 shares after 0001473289-26-000029
- Cloudflare (NET) — Form 4 of Sep 15, 2026 (Chief Financial Officer): shares withheld for tax of 2,944 at $327.23; 200,239 shares after 0001473289-26-000027
- Cloudflare (NET) — Form 4 of Aug 17, 2026 (Chief Financial Officer): conversion of 10,000; open-market sale of 900 at $305.25; 500,408 shares after 0001473289-26-000025
- Cloudflare (NET) — Form 4 of Aug 15, 2026 (Chief Financial Officer): shares withheld for tax of 2,944 at $315.78; 203,183 shares after 0001473289-26-000023
- Cloudflare (NET) — Form 4 of Aug 4, 2026 (Chief Financial Officer): option exercise or conversion of 55,000 at $44.72; open-market sale of 53,861 at $300.28; 206,127 shares after 0001473289-26-000021
- Cloudflare (NET) — Form 4 of Jul 17, 2026 (Chief Financial Officer): shares withheld for tax of 2,943 at $281.75; conversion of 10,000; 503,352 shares after 0001473289-26-000018
- Cloudflare (NET) — Form 4 of Jun 17, 2026 (Chief Financial Officer): shares withheld for tax of 2,944 at $228.48; conversion of 10,000; 506,295 shares after 0001473289-26-000016
- Cloudflare (NET) — Form 4 of May 18, 2026 (Chief Financial Officer): shares withheld for tax of 9,667 at $199.81; conversion of 10,000; 509,239 shares after 0001473289-26-000014
- Cloudflare (NET) — Form 4 of Apr 17, 2026 (Chief Financial Officer): shares withheld for tax of 2,944 at $178.65; conversion of 10,000; 518,906 shares after 0001473289-26-000012
- Cloudflare (NET) — Form 4 of Mar 17, 2026 (Chief Financial Officer): shares withheld for tax of 2,943 at $212.45; conversion of 10,341; 521,850 shares after 0001473289-26-000010
- Cloudflare (NET) — Form 4 of Feb 20, 2026 (Chief Financial Officer): conversion of 10,000; open-market sale of 8,279 at $177.18; 382,677 shares after 0001473289-26-000006
- Cloudflare (NET) — Form 4 of Feb 15, 2026 (Chief Financial Officer): shares withheld for tax of 20,477 at $195.85; 117,009 shares after 0001473289-26-000004
- Cloudflare (NET) — Form 4 of Feb 6, 2026 (Chief Financial Officer): grant or award of 142,116; 227,568 shares after 0001473289-26-000008
- Cloudflare (NET) — Form 4 of Jan 20, 2026 (Chief Financial Officer): conversion of 10,000; open-market sale of 928 at $176.27; 434,711 shares after 0001473289-26-000002
- Cloudflare (NET) — Form 4 of Dec 22, 2025 (Chief Financial Officer): conversion of 10,000; open-market sale of 353 at $198.64; 434,711 shares after 0001473289-25-000017
Sources: SEC Schedules 13D and 13G (stakes above 5%, which count everything a person votes or can acquire within 60 days) and Forms 3, 4 and 5 (the shares a director, officer or 10% owner holds, filed within two business days of each trade). Values at the last price.