Joel Greenblatt's position in Owens Corning is currently worth $7.53 Million. That's 0.13% of their equity portfolio (175th largest holding). The first Owens Corning trade was made in Q4 2010. Since then Joel Greenblatt bought shares 21 more times and sold shares on twenty occasions. The stake costed the investor $3.42 Million, netting the investor a gain of 120% so far.