Tenstorrent Leads $4.5B Week as AI Dominates Startup Megadeals

AI chip developer Tenstorrent raised $1.5 billion in Series E funding, capping a week in which U.S. startups pulled in more than $4.4 billion across the ten largest venture rounds.

Crunchbase tracked the deals for the week of Oct. 17-23, 2026. AI drove the lineup, but the money spread across biotech, space tech and defense. Trace Capital and Innovation X led the Tenstorrent round, which valued the Santa Clara company at $6.2 billion. Tenstorrent is 10 years old.

Which startups raised the most?

Flapping Airplanes, $1 billion, foundational AI. The San Francisco AI lab builds models that cost less to train and run. Lux Capital and Index Ventures led the Series A. The round landed less than 10 months after the year-old startup closed a $180 million seed round — a rare seed-to-A leap of that size.

ASI, $325 million, AI for critical infrastructure. ASI builds AI to secure and operate infrastructure in aviation, transportation and defense. Spark Capital led the Series C at a $3 billion valuation. The company is based in Boston.

Xona, $250 million, space tech. Xona is developing a next-generation version of GPS. Future Ventures led the Series D, which valued the Burlingame, California company at $2.4 billion.

Pathos AI, $237 million, biotech. Pathos applies AI to drug development. Bristol-Myers Squibb led the Series E at a post-money valuation around $3 billion. The company is headquartered in New York.

Warp Sciences, $215 million, AI and robotics. The startup applies AI and robotics to develop medicines faster. Lightspeed Venture Partners led the Series A.

Three companies tied at $200 million:

• Whop, an online business marketplace for entrepreneurs. Sequoia Capital and Shopify Ventures led the Series D, valuing the New York company at $5.1 billion.
• Star Therapeutics, a South San Francisco drug developer. OrbiMed and Janus Henderson Investors led the round. In July, Incyte agreed to buy Star's subsidiary Vega Therapeutics in a deal worth up to $2 billion.
• Warhound, the week's quirkiest deal. The startup breeds working dogs for U.S. military forces and emergency responders, and it launched from stealth with $200 million in seed funding. Backers include Sequoia Capital and 8VC. Palmer Luckey, founder of Anduril Industries, co-founded the company and plans to equip the dogs with Anduril technology.

Arda Industries, $160 million, AI manufacturing software. The San Francisco startup builds AI-powered software for manufacturing engineering. Altimeter Capital, Accel and Khosla Ventures co-led the Series A at a $1.5 billion valuation. Arda also disclosed a previously unannounced $72 million seed round.

What does the week signal for investors?

AI kept its grip on the top of the market, but the deals ranged wide. Foundational AI, chip design, critical infrastructure, robotics and manufacturing software all drew nine-figure checks. Biotech took three of the ten slots when counting Warp Sciences alongside Pathos and Star Therapeutics.

The seed stage also carried unusual weight. Warhound's $200 million seed for military dogs and Arda's $72 million seed show investors still willing to fund unproven companies at scale — provided the founding team or the defense angle justifies the risk. Luckey's involvement gives Warhound a direct line to Anduril's technology stack and its government customer base.

Speed mattered too. Flapping Airplanes went from a $180 million seed to a $1 billion Series A inside 10 months, matching the compressed fundraising timelines that marked the strongest AI companies of the cycle.

Crunchbase notes its methodology covers announced rounds by U.S.-based companies for Oct. 17-23, 2026, with some rounds reported late and small lags possible. 8VC, a Warhound backer, is an investor in Crunchbase and has no say in its editorial process.

Next week's list will show whether defense-adjacent bets like Warhound remain outliers or start a trend of their own.