Thomas J. Seifert

Companies

• CloudflareChief financial officer Sep 12, 2019 to now¹
• WolfspeedBoard member Dec 9, 2024 to Feb 3, 2025²
• IPG PhotonicsBoard member Jun 3, 2014 to May 25, 2022³
• Gen DigitalChief financial officer Mar 19, 2014 to Jun 14, 2016⁴
• AMDChief financial officer Oct 16, 2009 to Jun 19, 2012⁵
• AMDChief executive officer Feb 17, 2011 to Nov 10, 2011⁶

Holdings

Stock this person has reported owning, from the forms officers and directors file with the SEC. See the biggest insider stakes.

Shares held

• AMD AMD151,842 shares⁷$80.4M at $529.23May 9, 2012
• Cloudflare NET200,239 shares⁸$59.9M at $299.30Sep 21, 2026
• IPG Photonics IPGP8,946 shares⁹$641.2K at $71.67May 24, 2022
• Wolfspeed WOLF20,476 shares¹⁰$495.1K at $24.18Feb 3, 2025

As of each latest filing. The line shows shares held over time.

Recent filings

• Sep 17, 2026Sold 100 shares at $336.51 of Cloudflare⁸
• Sep 17, 2026Sold 600 shares at $335.32 of Cloudflare⁸
• Sep 17, 2026Sold 1,868 shares at $334.59 of Cloudflare⁸
• Sep 17, 2026Sold 2,632 shares at $333.62 of Cloudflare⁸
• Sep 17, 2026Sold 1,604 shares at $332.50 of Cloudflare⁸
• Sep 17, 2026Sold 1,196 shares at $331.59 of Cloudflare⁸
• Sep 17, 2026Sold 700 shares at $330.23 of Cloudflare⁸
• Sep 17, 2026Sold 700 shares at $329.37 of Cloudflare⁸
• Sep 17, 2026Sold 300 shares at $328.04 of Cloudflare⁸
• Sep 17, 2026Sold 100 shares at $326.56 of Cloudflare⁸
• Sep 17, 2026Sold 100 shares at $320.89 of Cloudflare⁸
• Sep 17, 2026Sold 100 shares at $318.90 of Cloudflare⁸
• Sep 17, 2026Converted 10,000 shares of Cloudflare⁸
• Sep 15, 2026Shares withheld for tax 2,944 shares at $327.23 of Cloudflare¹¹
• Aug 17, 2026Sold 100 shares at $314.61 of Cloudflare¹²
• Aug 17, 2026Sold 200 shares at $312.32 of Cloudflare¹²
• Aug 17, 2026Sold 300 shares at $309.07 of Cloudflare¹²
• Aug 17, 2026Sold 3,100 shares at $308.23 of Cloudflare¹²
• Aug 17, 2026Sold 2,456 shares at $307.29 of Cloudflare¹²
• Aug 17, 2026Sold 2,944 shares at $306.24 of Cloudflare¹²
• Aug 17, 2026Sold 900 shares at $305.25 of Cloudflare¹²
• Aug 17, 2026Converted 10,000 shares of Cloudflare¹²
• Aug 15, 2026Shares withheld for tax 2,944 shares at $315.78 of Cloudflare¹³
• Aug 4, 2026Sold 1,139 shares at $301.00 of Cloudflare¹⁴
• Aug 4, 2026Sold 53,861 shares at $300.28 of Cloudflare¹⁴