PRIMECAP Management, an asset manager overseeing $132.11B in disclosed equity holdings (SEC CIK 0000763212). The latest portfolio (2025Q4) discloses 319 positions across 11 sectors, with the largest positions in LLY, MU and GOOGL. On a mark-to-market basis the tracked portfolio has returned 41.7% since 2024Q1. OpenStocks tracks 8 consecutive quarterly snapshots for this manager — every position change, new entry, and exit is logged below.