Ken Griffin's position in Penumbra is currently worth $18.8 Million. That's 0.02% of their equity portfolio (816th largest holding). The first Penumbra trade was made in Q3 2015. Since then Ken Griffin bought shares 43 more times and sold shares on 33 occasions. The stake costed the investor $17.5 Million, netting the investor a gain of 7.4% so far.