The top-up Fund will provide Iron Pillar additional capital to back specific Fund I portfolio companies. : Iron Pillar, a venture growth investor specializing in mid-stage technology investments in India, on Monday announced the successful closing of its $45 million top-up fund. This fund will top-up Iron Pillar Fund-I that held its final close in 2018 with capital commitments of $90 million. The top-up fund will provide Iron Pillar additional capital to back specific Fund-I portfolio companies that are thriving even in the current market conditions.