Joel Greenblatt's position in Interdigital is currently worth $3.28 Million. That's 0.05% of their equity portfolio (481st largest holding). The first Interdigital trade was made in Q4 2010. Since then Joel Greenblatt bought shares 25 more times and sold shares on 25 occasions. The stake costed the investor $2.21 Million, netting the investor a gain of 48% so far.