Hedge funds have increased their ownership of MASI, NTNX and TWLO. : Should you buy stocks that hedge funds are buying? Not blindly, and no, marathoning all 3 seasons of Showtime’s Billions doesn’t count as proper research. Instead, for all the Bobby Axelrod wannabes out there, monitoring which stocks hedge funds are buying is a useful way to identify investment opportunities. Hedge funds are secretive but they are legally obligated to disclose their long equity positions every quarter via 13F filings.