Billionaire Mark Stevens sold $947 million of Nvidia in three months, more than any insider in America

American billionaire Mark Stevens, a venture capitalist who sits on Nvidia’s board and ranks as its second-largest individual shareholder, was the biggest insider seller of stock in the United States in the third quarter, offloading 4,236,740 shares for about $946.6 million, according to Bloomberg, citing data compiled by the Washington Service.

Stevens, a former Sequoia Capital partner who joined Nvidia’s board in 2008 and has held the shares for decades, is worth about $12.2 billion on the Bloomberg Billionaires Index after the sales. Only chief executive Jensen Huang holds more Nvidia stock among individuals.

The rest of the top six was heavy with technology money. Jayshree Ullal, chairman and chief executive of Arista Networks, the data-center networking company that sells into the same AI buildout as Nvidia, came second with 2,226,435 shares sold for about $446 million. Jeff Bezos was sixth, selling just over 1.2 million Amazon shares for roughly $346.5 million under a pre-arranged plan adopted in November 2025 that allows him to sell up to 15 million shares worth more than $4 billion. Stevens, Ullal and Bezos together are worth about $302 billion, Bloomberg said.

In between were three sellers from outside the chip-and-cloud core: Illumina director Keith Meister, the Corvex Management founder, third at about $436 million; SharkNinja chairman Xuning Wang, fourth at about $401 million after the board granted him a one-time waiver to sell; and CoreWeave chairman and chief executive Michael Intrator, fifth at about $347 million in the AI infrastructure company he took public last year.

The timing explains some of it. AI shares fell in July as investors questioned the scale of capital flowing into the sector, recovered partially, then dropped again in mid-September when Anthropic’s Dario Amodei and OpenAI’s Sam Altman publicly called for a slowdown in frontier AI development, a call Elon Musk endorsed and that sent the Philadelphia semiconductor index down 5.9% in a day. Most of the stocks have since rebounded. Nvidia’s valuation on a forward earnings basis approached its lowest in more than a decade during the quarter, Bloomberg noted, which is one reason an insider might sell: not because the shares are expensive but because the position is enormous.

Bezos is the clearest case of selling by schedule rather than sentiment. His plan predates the quarter, and Amazon has since become the fifth company to cross $3 trillion in market value, after Nvidia, Alphabet, Microsoft and Apple; his sales fund Blue Origin and his philanthropy and have continued through every rally.

The second quarter’s list had been almost entirely AI insiders. The third quarter’s drew in healthcare: United Therapeutics chairman and chief executive Martine Rothblatt and BeOne Medicines chairman and chief executive John Oyler both appeared, Bloomberg said, a sign that biotech executives found their own moment to take money off the table.

Insider sales are disclosed within two business days under U.S. rules and are not in themselves a signal; many are tax-driven, diversification-driven or pre-scheduled. What the quarter shows is scale. The six largest sellers alone converted about $2.9 billion of stock into cash in 92 days, most of it from companies whose valuations rest on the AI buildout continuing. Stevens, who has watched Nvidia from the inside for 18 years, chose this quarter to turn nearly $1 billion of it into something else.