Ken Griffin acquired 2.73 Million MerckInc shares worth $347 Million. That's 0.35% of their equity portfolio (38th largest holding). The first MerckInc trade was made in Q2 2013. Since then Ken Griffin bought shares 49 more times and sold shares on 50 occasions. The stake costed the investor $208 Million, netting the investor a gain of 67% so far.