Stanford spinout Simile closed a $200 million Series B led by Greenoaks and Index just months after a $100 million Series A, reaching a $2 billion valuation on rapid revenue growth for its behavioral synthetic-user platform. CVS Health Ventures participated, underscoring healthcare interest beside broader enterprise traction. It matters as another ultra-fast AI unicorn in the simulation and research layer of software. Caveat: headline valuations can outrun durable unit economics, so treat round size as a signal rather than proof of lasting advantage.