George Soros's position in Alnylam Pharmaceuticals is currently worth $19.3 Million. That's 0.57% of their equity portfolio (54th largest holding). The first Alnylam Pharmaceuticals trade was made in Q1 2014. Since then George Soros bought shares four more times and sold shares on four occasions. The stake costed the investor $15.4 Million, netting the investor a gain of 25% so far.