SEC Form 4 reporting owner
Seifert Thomas J
Seifert Thomas J has filed 101 Form 4 transactions reported between December 22, 2025 and September 17, 2026, as Chief Financial Officer of Cloudflare, Inc..
Name as filed: SEIFERT THOMAS J
Open-market buys, 24 mo
None
reported
Open-market sales, 24 mo
$44.9M
81 lines
Companies
1
with Form 4 filings
Latest transaction
Sep 17, 2026
transaction date
Roles and reported holdings
Transaction history
All 101 reported transactions, newest first. Every row links to the Form 4 on SEC EDGAR.
| Date | Company | Type | Shares | Price | Value | Owned after | Filing |
|---|---|---|---|---|---|---|---|
| Sep 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 600 | $335.32 | $201K@ $335.32 | 108,002 | Form 4 |
| Sep 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,868 | $334.59 | $625K@ $334.59 | 108,602 | Form 4 |
| Sep 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,632 | $333.62 | $878K@ $333.62 | 110,470 | Form 4 |
| Sep 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,604 | $332.50 | $533K@ $332.50 | 113,102 | Form 4 |
| Sep 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,196 | $331.59 | $397K@ $331.59 | 114,706 | Form 4 |
| Sep 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 700 | $329.37 | $231K@ $329.37 | 116,602 | Form 4 |
| Sep 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 300 | $328.04 | $98K@ $328.04 | 117,302 | Form 4 |
| Sep 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 100 | $318.90 | $32K@ $318.90 | 117,802 | Form 4 |
| Sep 17, 2026 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,000 | — | — | 117,902 | Form 4 |
| Sep 15, 2026 | NETChief Financial Officer | Shares withheld for tax or exercise priceCode F · direct | 2,944 | $327.23 | $963K@ $327.23 | 107,902 | Form 4 |
| Aug 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 100 | $314.61 | $31K@ $314.61 | 110,846 | Form 4 |
| Aug 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 200 | $312.32 | $62K@ $312.32 | 110,946 | Form 4 |
| Aug 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 300 | $309.07 | $93K@ $309.07 | 111,146 | Form 4 |
| Aug 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 3,100 | $308.23 | $956K@ $308.23 | 111,446 | Form 4 |
| Aug 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,456 | $307.29 | $755K@ $307.29 | 114,546 | Form 4 |
| Aug 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,944 | $306.24 | $902K@ $306.24 | 117,002 | Form 4 |
| Aug 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 900 | $305.25 | $275K@ $305.25 | 119,946 | Form 4 |
| Aug 17, 2026 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,000 | — | — | 120,846 | Form 4 |
| Aug 15, 2026 | NETChief Financial Officer | Shares withheld for tax or exercise priceCode F · direct | 2,944 | $315.78 | $930K@ $315.78 | 110,846 | Form 4 |
| Aug 4, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,139 | $301.00 | $343K@ $301.00 | 113,790 | Form 4 |
| Aug 4, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 53,861 | $300.28 | $16.2M@ $300.28 | 114,929 | Form 4 |
| Aug 4, 2026 | NETChief Financial Officer | Option exerciseCode M · direct | 55,000 | $44.72 | $2.5M@ $44.72 | 168,790 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 800 | $279.91 | $224K@ $279.91 | 114,090 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,201 | $278.76 | $335K@ $278.76 | 114,890 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 3,299 | $277.68 | $916K@ $277.68 | 116,091 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,741 | $276.63 | $482K@ $276.63 | 119,390 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,559 | $275.79 | $430K@ $275.79 | 121,131 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 500 | $274.60 | $137K@ $274.60 | 122,690 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 300 | $270.50 | $81K@ $270.50 | 123,190 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 100 | $267.76 | $27K@ $267.76 | 123,490 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 200 | $266.19 | $53K@ $266.19 | 123,590 | Form 4 |
| Jul 17, 2026 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,000 | — | — | 123,790 | Form 4 |
| Jul 15, 2026 | NETChief Financial Officer | Shares withheld for tax or exercise priceCode F · direct | 2,943 | $281.75 | $829K@ $281.75 | 113,790 | Form 4 |
| Jun 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,633 | $234.18 | $617K@ $234.18 | 117,333 | Form 4 |
| Jun 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 3,167 | $233.44 | $739K@ $233.44 | 119,966 | Form 4 |
| Jun 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 600 | $232.00 | $139K@ $232.00 | 123,133 | Form 4 |
| Jun 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 685 | $230.90 | $158K@ $230.90 | 123,733 | Form 4 |
| Jun 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 515 | $229.95 | $118K@ $229.95 | 124,418 | Form 4 |
| Jun 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 900 | $227.74 | $205K@ $227.74 | 125,833 | Form 4 |
| Jun 17, 2026 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,000 | — | — | 126,733 | Form 4 |
| Jun 15, 2026 | NETChief Financial Officer | Shares withheld for tax or exercise priceCode F · direct | 2,944 | $228.48 | $673K@ $228.48 | 116,733 | Form 4 |
| May 18, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 270 | $203.02 | $55K@ $203.02 | 212,014 | Form 4 |
| May 18, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,000 | $202.17 | $404K@ $202.17 | 212,284 | Form 4 |
| May 18, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 3,570 | $201.21 | $718K@ $201.21 | 214,284 | Form 4 |
| May 18, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,432 | $200.20 | $487K@ $200.20 | 217,854 | Form 4 |
| May 18, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 928 | $199.05 | $185K@ $199.05 | 220,286 | Form 4 |
| May 18, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 400 | $197.81 | $79K@ $197.81 | 221,214 | Form 4 |
| May 18, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 300 | $195.14 | $59K@ $195.14 | 221,614 | Form 4 |
| May 18, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 100 | $193.28 | $19K@ $193.28 | 221,914 | Form 4 |
| May 18, 2026 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,000 | — | — | 222,014 | Form 4 |
| May 15, 2026 | NETChief Financial Officer | Shares withheld for tax or exercise priceCode F · direct | 9,667 | $199.81 | $1.9M@ $199.81 | 212,014 | Form 4 |
| Apr 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 400 | $200.95 | $80K@ $200.95 | 221,681 | Form 4 |
| Apr 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,725 | $200.51 | $546K@ $200.51 | 222,081 | Form 4 |
| Apr 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,475 | $199.48 | $294K@ $199.48 | 224,806 | Form 4 |
| Apr 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 600 | $198.03 | $119K@ $198.03 | 226,281 | Form 4 |
| Apr 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,000 | $196.97 | $197K@ $196.97 | 226,881 | Form 4 |
| Apr 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,724 | $196.04 | $338K@ $196.04 | 227,881 | Form 4 |
| Apr 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,076 | $195.09 | $405K@ $195.09 | 229,605 | Form 4 |
| Apr 17, 2026 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,000 | — | — | 231,681 | Form 4 |
| Apr 15, 2026 | NETChief Financial Officer | Shares withheld for tax or exercise priceCode F · direct | 2,944 | $178.65 | $526K@ $178.65 | 221,681 | Form 4 |
| Mar 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,000 | $213.23 | $426K@ $213.23 | 224,625 | Form 4 |
| Mar 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 5,000 | $212.57 | $1.1M@ $212.57 | 226,625 | Form 4 |
| Mar 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 3,041 | $211.69 | $644K@ $211.69 | 231,625 | Form 4 |
| Mar 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 100 | $208.64 | $21K@ $208.64 | 234,666 | Form 4 |
| Mar 17, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 200 | $207.68 | $42K@ $207.68 | 234,766 | Form 4 |
| Mar 17, 2026 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,341 | — | — | 234,966 | Form 4 |
| Mar 15, 2026 | NETChief Financial Officer | Shares withheld for tax or exercise priceCode F · direct | 2,943 | $212.45 | $625K@ $212.45 | 224,625 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 100 | $195.19 | $20K@ $195.19 | 85,452 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 395 | $194.05 | $77K@ $194.05 | 85,552 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,766 | $193.12 | $534K@ $193.12 | 85,947 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 4,771 | $192.18 | $917K@ $192.18 | 88,713 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 8,133 | $191.13 | $1.6M@ $191.13 | 93,484 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,613 | $190.35 | $497K@ $190.35 | 101,617 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 300 | $188.77 | $57K@ $188.77 | 104,230 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 200 | $187.38 | $37K@ $187.38 | 104,530 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 500 | $186.10 | $93K@ $186.10 | 104,730 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 700 | $185.09 | $130K@ $185.09 | 105,230 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,000 | $183.78 | $184K@ $183.78 | 105,930 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,300 | $182.53 | $237K@ $182.53 | 106,930 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,500 | $181.82 | $273K@ $181.82 | 108,230 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,900 | $180.68 | $343K@ $180.68 | 109,730 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 2,400 | $179.51 | $431K@ $179.51 | 111,630 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 4,700 | $178.53 | $839K@ $178.53 | 114,030 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 8,279 | $177.18 | $1.5M@ $177.18 | 118,730 | Form 4 |
| Feb 20, 2026 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,000 | — | — | 127,009 | Form 4 |
| Feb 15, 2026 | NETChief Financial Officer | Shares withheld for tax or exercise priceCode F · direct | 20,477 | $195.85 | $4.0M@ $195.85 | 117,009 | Form 4 |
| Feb 6, 2026 | NETChief Financial Officer | Grant or awardCode A · direct | 142,116 | — | — | 227,568 | Form 4 |
| Jan 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 100 | $181.98 | $18K@ $181.98 | 137,486 | Form 4 |
| Jan 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 600 | $181.27 | $109K@ $181.27 | 137,586 | Form 4 |
| Jan 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,900 | $180.09 | $342K@ $180.09 | 138,186 | Form 4 |
| Jan 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,200 | $179.41 | $215K@ $179.41 | 140,086 | Form 4 |
| Jan 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 1,800 | $178.08 | $321K@ $178.08 | 141,286 | Form 4 |
| Jan 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 3,472 | $177.17 | $615K@ $177.17 | 143,086 | Form 4 |
| Jan 20, 2026 | NETChief Financial Officer | Open-market saleCode S · direct | 928 | $176.27 | $164K@ $176.27 | 146,558 | Form 4 |
| Jan 20, 2026 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,000 | — | — | 147,486 | Form 4 |
| Dec 22, 2025 | NETChief Financial Officer | Open-market saleCode S · direct | 483 | $203.35 | $98K@ $203.35 | 137,486 | Form 4 |
| Dec 22, 2025 | NETChief Financial Officer | Open-market saleCode S · direct | 3,328 | $202.37 | $673K@ $202.37 | 137,969 | Form 4 |
| Dec 22, 2025 | NETChief Financial Officer | Open-market saleCode S · direct | 4,836 | $201.52 | $975K@ $201.52 | 141,297 | Form 4 |
| Dec 22, 2025 | NETChief Financial Officer | Open-market saleCode S · direct | 1,000 | $200.58 | $201K@ $200.58 | 146,133 | Form 4 |
| Dec 22, 2025 | NETChief Financial Officer | Open-market saleCode S · direct | 353 | $198.64 | $70K@ $198.64 | 147,133 | Form 4 |
| Dec 22, 2025 | NETChief Financial Officer | Conversion of derivativeCode C · direct | 10,000 | — | — | 147,486 | Form 4 |
How this page is built
Every row comes from a Form 4 filed with the SEC, which officers, directors and holders of more than 10% of a company’s stock must file within two business days of a trade. Transactions are grouped by the reporting owner’s name as filed (spacing, capitals and punctuation ignored); two different people filing under an identical name would appear together, and one person filing under two spellings appears on two pages.
Open-market totals count code P purchases and code S sales over the last 24 months. The same trade reported on more than one filing is counted once; when another owner (for example a fund and its general partner) reports the identical trade, they are listed beside it. Holdings are the shares owned after the latest purchase, sale, gift or tax-withholding line, shown separately for direct and indirect ownership; an indirect figure is one holding line, not a total across every trust or entity.
This page describes what was filed with the SEC; it is not investment advice or a recommendation to buy or sell any security.