AdvertisementSKIP ADVERTISEMENTYou have a preview view of this article while we are checking your access. When we have confirmed access, the full article content will load.A week ago, we learned the news that Jensen Huang, the rock star C.E.O. of the chip-making company Nvidia, had acknowledged an affair with a woman U.S. intelligence officials believe to be a Chinese spy.

It turns out that may have been just the beginning. Shortly after revelations of a second affair, this time with a subordinate, Huang resigned.Nvidia’s stock has tumbled in the days since, losing hundreds of billions of dollars in value, and analysts have begun trying to process just how the downfall of one of the most important figures in the A.I. industry is going to play out.

One Silicon Valley venture capitalist recently called him “irreplaceable.”But why are Huang and Nvidia so irreplaceable — and is anything that cannot be replaced automatically vulnerable? Today I’m writing about power, vulnerability and choke points.ImageA tech conference in San Jose, Calif., in March.

Credit...Manuel Orbegozo for The New York TimesWhy there’s only one NvidiaLast week, as it became clear that Jensen Huang’s future at Nvidia might be in jeopardy, a meme began making the rounds on the internet. It showed a complicated, multitiered structure, delicately balanced on a tiny block.

The structure was labeled “entire global economy”; the block was labeled “Jensen Huang’s wife.”The meme is already outdated: Huang has resigned from his role as Nvidia’s C.E.O. (and it never made sense to put any of this on his wife). But the image still captured the idea that so much of the business world somehow came to depend on one man and his — now, it seems, questionable — judgment.Thank you for your patience while we verify access.

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