Jim Simons acquired 611 Berkshire Hathaway shares worth $325 Million. That's 0.49% of their equity portfolio (28th largest holding). The first Berkshire Hathaway trade was made in Q3 2013. Since then Jim Simons bought shares eighteen more times and sold shares on fifteen occasions. The stake costed the investor $304 Million, netting the investor a gain of 6.8% so far.