CSX (CSX) Institutional Ownership & Top Holders
The most recent SEC Form 13F filings (Q1 2026) show 5 hedge funds and institutional investors holding a combined 5.5M shares of CSX (CSX), valued at $226.4M. The median portfolio weight is 0.5%.
Institutional ownership changes in CSX reflect net selling, as the combined position decreased by 20.7M shares (79.0%) from the previous quarter.
Among 13F filers, the funds with the highest portfolio allocation to CSX are Locust Wood (3.2% of its 13F portfolio), Sound Shore Management (2.8%), and UTIMCO - The University of Texas (0.5%). In Q1 2026, Markel Group made the largest position increase (+0.1%), while PARK PRESIDIO CAPITAL made the largest reduction (-2.0%).
Top 5 Institutional Holders in CSX (CSX), Ranked by Portfolio Weight
Based on the latest SEC Form 13F filings (Q1 2026).
| # | Fund | Shares | Market Value | Portfolio Weight |
|---|---|---|---|---|
| 1 | Locust Wood | 2,868,822 | $117.8M | 3.2% |
| 2 | Sound Shore Management | 2,002,159 | $82.2M | 2.8% |
| 3 | UTIMCO - The University of Texas | 78,138 | $3.2M | 0.5% |
| 4 | Kahn Brothers Group | 36,481 | $1.5M | 0.3% |
| 5 | Markel Group | 530,000 | $21.8M | 0.2% |
- 5Institutional investors
- 5,515,600Shares held (disclosed)
- $226.4M13F market value
- 0.5%Median portfolio weight
Ownership History
Quarter-by-quarter share count, market value, and portfolio conviction weight (up to 5 of the heaviest weight-by-portfolio funds) of CSX. Sourced from 13F filings; reflects long equity positions only.
Quarter-over-Quarter ActivityQ1 2026
The biggest weight-increase and weight-decrease changes among funds that hold CSX. Deltas compare the selected filing to the previous reporting quarter.
Top buyers
- Markel Group+0.1% · +90,000 shares
Top sellers
- PARK PRESIDIO CAPITAL-2.0% · -667,932 shares
- Viking Global-1.3% · -13,817,539 shares
- Soroban Capital-1.1% · -4,072,561 shares
Ownership Statistics
- Funds holding
- 5
- Median weight
- 0.5%
- Largest holder
- Locust Wood · 3.2%
- Smallest holder
- Markel Group · 0.2%
- Shares held
- 5,515,600 (-20,721,921)
All Institutional HoldersSortable · searchable
All institutional investors (Max 50) holding CSX in the selected quarter. Click a fund name to drill into its full 13F portfolio.
| 1 | Locust Wood | 2,868,822 | $117.8M | 3.2% |
| 2 | Sound Shore Management | 2,002,159 | $82.2M | 2.8% |
| 3 | UTIMCO - The University of Texas | 78,138 | $3.2M | 0.5% |
| 4 | Kahn Brothers Group | 36,481 | $1.5M | 0.3% |
| 5 | Markel Group | 530,000 | $21.8M | 0.2% |
Institutional Investor Count Over Time
Number of institutional investors disclosing a long position in CSX CORP (CSX) each reporting quarter. Sourced from SEC Form 13F-HR filings.
See CSX CORP (CSX) insider transactions — SEC Form 4 →
Methodology & FAQ
Methodology: How We Track CSX Institutional Holdings
Our data is systematically aggregated directly from quarterly Form 13F-HR disclosures submitted to the U.S. Securities and Exchange Commission (SEC).
- Who Must File (Reporting Threshold): This dataset includes filings from U.S. institutional investment managers, hedge funds, mutual funds, university endowments, and family offices managing at least $100 million in Section 13(f) securities (including equities, options, convertibles, ETFs, and warrants).
- What is Included (Data Scope): We capture long positions in Section 13(f) securities for CSX CORP (CSX). By SEC regulation, 13F filings do not require the disclosure of short positions, non-U.S. holdings, or OTC derivatives. Listed options are excluded from portfolio weight calculations to ensure comparability across filers.
- Portfolio Weight Explained (Metric Definition): “Portfolio Weight” shows how much of a fund's total reported 13F portfolio value (excluding listed options) is allocated to CSX on the specific reporting date.
- How to Use This Data (Interpretation): Quarter-over-quarter changes in shares and portfolio weight reflect a combination of active trading and market price movements. These are descriptive metrics of fund allocation, not explicit buy or sell signals.
How do you measure hedge fund conviction and institutional concentration in CSX?
We evaluate fund conviction by looking at portfolio weight rather than just absolute share count. By tracking how the largest holders —such as Locust Wood , Sound Shore Management , and UTIMCO - The University of Texas as of Q1 2026— change their position sizing quarter-over-quarter, we help investors distinguish between deliberate position sizing changes and passive mark-to-market drift.
Does the CSX ownership data include short interest or options?
SEC Form 13F mandates the disclosure of long positions in Section 13(f) securities, which includes equities and listed options (put and call contracts), but excludes short interest, swaps, and OTC derivatives by regulatory design. On this platform, listed options are excluded from portfolio weight calculations to ensure comparability across filers.
Are family offices and university endowments included in this CSX data?
Yes. In addition to traditional hedge funds and large asset managers, any institutional entity exercising investment discretion over at least $100 million in Section 13(f) securities must file a Form 13F. This explicitly includes single-family offices and university endowments. If a qualifying family office or endowment holds CSX stock, their allocation is systematically aggregated alongside traditional fund data.
When is the institutional ownership data updated, and is there a reporting lag?
Institutional investment managers are required to file their Form 13F within 45 days after the end of a calendar quarter (the standard “T+45” window). Our platform re-ingests new filings from the SEC EDGAR database on a nightly cycle, typically within 24–48 hours of publication, providing a point-in-time snapshot of reported consensus positioning for CSX as of each filing date.