Southeastern Asset runs Longleaf, an asset manager overseeing $2.25B in disclosed equity holdings (SEC CIK 0000807985). The latest portfolio (2025Q4) discloses 53 positions across 10 sectors, with the largest positions in CNX, MAT and IAC. On a mark-to-market basis the tracked portfolio has returned 4.2% over the past year. OpenStocks tracks 40 consecutive quarterly snapshots for this manager — every position change, new entry, and exit is logged below.
Methodology:TWR tiles chain-link quarterly mark-to-market across consecutive filings (GIPS-compliant) ·actual tiles use a real 13F snapshot marked to today ·backtest tiles re-price the current book to historical prices.
Performance overview
We mark Southeastern Asset (Longleaf)'s disclosed portfolio to current market prices and compare its growth against the S&P 500 (SPY). Southeastern's portfolio is 4.2% over the last 12 months · 62.1% since 2016Q1.
Portfolio growth vs SPY
Rebased to 100 at 2021Q2 · through 2025Q4
Southeastern Asset
+32.9%
SPY
+69.5%
Alpha
-36.7pp
Portfolio line is the GIPS-compliant time-weighted return chain-linked across the manager's quarterly 13F filings — unaffected by capital flows. Quarters with insufficient held-through coverage are skipped, which can briefly flatten the line.