Mario Gabelli started to build up the position in BlackRock Institutional Trust Company N.A. - iShares Core S&P 500 ETF in Q4 2002 and continued to invest until Q1 2019. Since then they sold 1 Thousand shares. The investor sold all their shares in Q2 2019 and doesn't own any shares in BlackRock Institutional Trust Company N.A. - iShares Core S&P 500 ETF anymore.