Banking tech startup Zeta is inching closer to the much sought-after unicorn status as it engages with investors to finalize a new round, two sources familiar with the matter told TechCrunch. SoftBank Vision Fund 2 is in advanced stages of talks to lead a ~$250 million Series D round in the five-year-old startup, the sources said. The investment proposal values the Indian startup, co-founded by high-profile entrepreneur Bhavin Turakhia, at over $1 billion, up from $300 million in its maiden external funding (Series C) in 2019. The round has yet…