WS Investment Co. was formed in 1978. They are the investment fund of law firm Wilson Sonsini Goodrich & Rosati and has been managed by Mario Rosati since 1978.
WS Investment Co. has invested in over 48 companies, including pre-IPO investments in Google, Brocade, Juniper Networks and Avanex. Other investments include Crowdz, Driveroo, Cloudian, Swiftmile, Savitude, GenXComm, VRChat, iAssay, Stache and Forge Therapeutics.
Their exits include Netflix, T2 Biosystems, Wayin, AnaptysBio, Kythera Biopharmaceuticals, Ambarella, Conscious Box, Ardian, Greystripe and Kintera.