Just five months after emerging from stealth and announcing a $100 million Series A led by Index Ventures, it has closed a $200 million Series B at a $2 billion valuation, the startup says. The B round was led by Greenoaks with participation from Index, Hanabi, Bain Capital Ventures, A*, Factory, Definition, and CVS Health Ventures. The startup offers simulated users for areas like marketing and product research. However, simulating users for research is a promising area. Other startups in this vein have also caught VC attention, such as Aaru, which raised a Series A in December, also at a hefty “headline” $1 billion valuation.