Ray Dalio’s Bridgewater Associates made several stock purchases during the first quarter. However, the stock purchases’ size compared to the fund’s ETF holdings is very small. Biogen (BIIB) was Bridgewater’s largest stock holding. Biogen contributed 0.35% of the fund’s total holdings. Bridgewater increased its position in the stock 424% during the first quarter. Bridgewater first took a stake in Biogen in the first quarter of 2018.
On March 21, Biogen and Eisai issued a press release announcing the termination of their aducanumab research program aimed at the drug study for Alzheimer’s disease. After the news, Biogen stock fell ~30%.