WaterBridge Ventures has exited its investment in online education startup Unacademy after three top venture capital investment firms — Sequoia Capital, SAIF Partners and Nexus Venture Partners — bought out the earlystage investor’s stake in the Bengaluru-based company. The development comes soon after Unacademy raised $21 million (Rs.143 crore) in its Series C funding round, which was led by its three existing marquee investors in July, and which valued the three-year-old company at about $100 million.