Nearly 50% of Y Combinator’s Spring 2025 startup batch builds AI agents

The new AAA is “All About Agents.”

Y Combinator has reached a new milestone in its AI focus, with 67 of the 144 startups in its Spring 2025 batch—nearly 50%—building AI agents or tools for creating them. This represents both a significant increase from previous cohorts and a clear signal of where the startup ecosystem is heading, as the famed accelerator continues to reflect broader market trends while commanding premium valuations that have some investors reconsidering their approach.

The big picture: YC’s AI agent concentration has grown from 58 out of 163 companies in Winter 2025 to 67 out of 144 in Spring 2025, continuing the accelerator’s trajectory toward AI-focused startups that began intensifying after ChatGPT‘s launch.

Why this matters: The shift reflects the broader startup ecosystem’s embrace of AI agents as the next frontier, with investors noting that virtually every company they’re evaluating now incorporates AI technology in some form.

What investors are saying: The AI focus has created a valuation premium that’s reshaping how VCs approach YC deals.

• “I think people have complained about YC every year that it’s too oversaturated with X thing,” said Andy McLoughlin, managing partner at Uncork Capital. “But everything now is AI: every company we’re funding, that we’re looking at, that’s going through YC is using AI, and the question is are they pretty good or are they really f—— good?”
• “YC is playing a total different game,” said Matt Cohen, founder and managing partner at Ripple Ventures. “There’s this dislocation between what we’re doing our deals at and the traditional YC round. We’re just not playing that game.”

Key details: The current AI excitement has helped numerous companies in this batch command valuations upward of $70 million post-money, according to investors who spoke to PitchBook.

• Many startups have already completed their fundraising before Demo Day, with one founder reporting they were instructed to begin fundraising just a week or two prior to the event.
• The in-person Demo Day on Wednesday saw many VCs attending primarily to socialize and celebrate founders they had already funded.

The broader context: Not all investors are deterred by the premium pricing, with some viewing it as justified for access to YC’s curated talent pool.

• “I am going to give YC credit,” said Terrence Rohan, managing director at Otherwise Fund. “Are they a premium pool? Yes, they are, and should there be premium prices for that? I am OK with that.”