Ken Griffin acquired 2.73 Million MerckInc shares worth $357 Million. That's 0.36% of their equity portfolio (34th 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 71% so far.