Rain co-founded Livonia Partners. He has one of the most extensive investment and entrepreneurial track records in the Baltics across a wide range of industries. In 1991 in Tallinn, Rain co-founded Hansabank, the largest pan-Baltic financial institution. The bank grew both organically and via acquisitions into the largest bank in the Baltics, and was sold to Swedbank in 1998. In 1999 Rain created and later successfully exited a venture capital fund, New Economy Ventures, having invested in seven technology companies, including Forticom and CV-Online. The fund returned to its investors 10x their capital. In 1999 Rain also founded LHV Group, a pan-Baltic banking group, where he remains in a supervisory role. In 2005 he co-founded LHV Capital with Mindaugas Utkevičius and has invested into Veju Spektras, Archyvu Centras, Qvalitas Medical Centre, and Baltic Ticket Holdings.