Dan Sundheim runs D1 Capital, a hedge fund overseeing $10.70B in disclosed equity holdings (SEC CIK 0001747057). The latest portfolio (2025Q4) discloses 42 positions across 10 sectors, with the largest positions in CART, CLH and FLS. On a mark-to-market basis the tracked portfolio has returned 27.7% over the past year. OpenStocks tracks 29 consecutive quarterly snapshots for this manager — every position change, new entry, and exit is logged below.