In the AI era, the lifespan of a startup has never been more precarious.

Companies that looked poised to become the next billion-dollar hits can find themselves transformed overnight into the equivalent of a VCR or fax machine business, made obsolete by the latest update from Anthropic, Google, or OpenAI.

If you’re a venture capitalist whose job it is to invest in startups, that’s a scary thought. Anything in your portfolio that pre-dates ChatGPT’s November 2022 launch is an investment made in a different world—and a lot of those investments were made at unicorn valuations. That means that any VC worth their salt should be hyper focused on reevaluating all the startups in their orbit on an almost weekly basis to see who has a moat, who is toast, and who they need to help pivot or land softly.

Fortune’s Allie Garfinkle spoke to a number of VCs about how they’re doing this triage exercise. Those that spoke to her on record seemed to couch the situation, with one citing that only 10% to 20% of their portfolio was at risk.

That ratio feels off to me, given the amount of money that’s been pumped into the startup ecosystem over the past decade and the types of businesses that were hot in the pre-AI days. I would expect it to be the inverse, with only 10% to 20% of the startups being secure in this unprecedented moment.

When I tweeted my skepticism, one honest VC, Bullish’s Mike Duda, agreed. Duda has been one of New York’s most successful angel investors over the past decade, putting early money into companies like Warby Parker, Casper, and Peloton.

“Yes, it’s higher,” he replied.

It’s hard to blame the VC industry for clamming up about the issue. There’s little upside to publicizing the predicament. And the road ahead—particularly for startup accelerators like Y Combinator, which produce classes of hundreds of startups every year—is particularly challenging. What do you say to the founders whose businesses are now irrelevant? And, perhaps more importantly, how do you vet new founders on viable ideas in this uncertain moment?

As any parent trying to advise their kids on choosing a college major or career today can attest, it’s not easy. The transition to an AI economy is still very much a work in progress, and knowing what to hold on to and what to say goodbye to can feel overwhelming.

Check out Garfinkle’s take on the mad dash of startup investors to reevaluate their portfolios for the AI era.

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