Ken Griffin acquired 1.3 Million Costco Wholesale shares worth $1.28 Billion. That's 1.26% of their equity portfolio (3rd largest holding). The first Costco Wholesale trade was made in Q2 2013. Since then Ken Griffin bought shares 65 more times and sold shares on 49 occasions. The stake costed the investor $493 Million, netting the investor a gain of 159% so far.