Howard Marks started to build up the position in BlackRock Institutional Trust Company N.A. - iShares iBoxx USD High Yield Corporate Bond ETF in Q4 2018. Since then they sold 123 Thousand shares. The investor sold all their shares in Q1 2019 and doesn't own any shares in BlackRock Institutional Trust Company N.A. - iShares iBoxx USD High Yield Corporate Bond ETF anymore.