Investment strategy: A woman walks past a logo of the SoftBank Group in Tokyo. The company SoftBank is now one of the largest investors in the highly undervalued Swiss pharmaceutical giant Roche. — AFP UNICORNS used to be the almost exclusive focus of SoftBank Group Corp. But now hedge funds are entering chief executive officer Masayoshi Son’s backyard, chasing these billion-dollar plus tech startups in droves. As the competition heats up, can SoftBank retain its edge in venture capital? Could it change its investing style to stock picking or perhaps even activism?