Ken Griffin's position in Quest Diagnostics is currently worth $16.4 Million. That's 0.02% of their equity portfolio (904th largest holding). The first Quest Diagnostics trade was made in Q2 2013. Since then Ken Griffin bought shares 53 more times and sold shares on 45 occasions. The stake costed the investor $15.3 Million, netting the investor a gain of 7.2% so far.