Ken Griffin's position in Dexcom is currently worth $474 Million. That's 0.55% of their equity portfolio (14th largest holding). The investor owns 1.07% of the outstanding Dexcom stock. The first Dexcom trade was made in Q2 2013. Since then Ken Griffin bought shares 50 more times and sold shares on 40 occasions. The stake costed the investor $248 Million, netting the investor a gain of 91% so far.