Viral AI Startup Instinct Has Raised $350M at a $2.5B Valuation

Instinct, a personal AI-assistant startup founded by 23-year-old Noah Shinn, has raised a total of $350 million after a $250 million Series B co-led by Index Ventures and Benchmark valued the company at $2.5 billion — up from a $50 million valuation just months earlier.

The company, operated by Spear Street Technology, was founded in 2025 after Shinn left Sierra, the customer-service AI company. Instinct positions itself as an agent that organizes your life: users connect it to their apps and devices and interact with it directly through texts and calls, rather than through a traditional app interface.

Instinct remains in private beta and keeps a deliberately minimal public presence, but its rapid rise hasn't come without scrutiny — critics have raised concerns over the extensive system permissions the assistant requests and contractual terms that some describe as overly broad.