CSX Corporation

The full register, from 13F filings

The Register tab above is hand research: a dozen holders, each traced to the filing it came from. This asks the same question of the whole market for the quarter ended 31-mar-2026, where 1,842 managers reported a position. Broad where the research is deep, and shallow in the ways a 13F always is.

Built from 13F filings, which report US listed, long, US custodied positions only. A register from this source is a floor rather than a level: a holder's true position can be far larger, as BlackRock's ASML stake shows at 1.28m shares in a 13F against 26.3m in its 13G/A. Holdings held through derivatives, outside US custody, or below a manager's reporting obligation do not appear. Where a holder is marked as a family, its total sums several separate filing entities and describes something no single filing describes; the constituent entities and their share counts are listed so the total can be checked. That roll-up can legitimately exceed the family's own Schedule 13G, because a 13G is filed by one legal entity: Vanguard reports Alphabet through ten advisory entities, and The Vanguard Group Inc itself reported zero after its January 2026 disaggregation.

What a reader needs to know to read these numbers

• CSX has a single class of common stock, $1 par value (5.4 billion shares authorized), one vote per share, listed on the Nasdaq Global Select Market under the symbol CSX. There is no dual-class structure and no founder or family control block.
• Conrail and TTX are the only individually named equity-method investees broken out in Note 15 of the FY2025 10-K. A third line, 'Other Investments in Affiliates', totals $278 million at December 31, 2025 ($263 million at December 31, 2024) and is not itemized by investee anywhere in the 10-K or the Q2 FY2026 10-Q, so per the brief it is excluded from holdings rather than attributed to a guessed investee. Total 'Investments in affiliates and other companies' on the balance sheet was $2,634 million at December 31, 2025 ($1,301m Conrail + $1,055m TTX + $278m other) and $2,675 million at June 30, 2026 (not broken out by investee in the 10-Q).
• TTX percentage established independently for CSX rather than reused from Union Pacific's file: CSX's FY2025 10-K states CSX owns 'about 20 percent' of TTX, materially different from Union Pacific's separately disclosed 37.03 percent economic interest in the same company (union-pacific.json). The two figures are not interchangeable and come from each railroad's own filings.
• No definitive merger or combination agreement involving CSX was found. The most recent 10-Q (period ended June 30, 2026, filed July 22, 2026) and the accompanying 8-Ks contain no reference to a merger, business combination, or acquisition involving CSX as a party; searches for 'merger', 'BNSF', 'combination' and 'Berkshire' returned nothing relevant to CSX itself (the only 'Berkshire' and 'merger' hits concern an unrelated Occidental Petroleum/Berkshire Hathaway chemicals-business transaction referenced in a legal-proceedings footnote). 2025 and 2026 press speculation about railroad consolidation involving CSX (e.g. in the context of the pending Union Pacific/Norfolk Southern merger) is not reflected in any CSX filing as of this research and is therefore not recorded as a holding, register row, or contingent basis.
• Vanguard's most recent Form 13F-HR is for the quarter ended December 31, 2025 (filed January 29, 2026: 175,198,067 shares, $6.35 billion). For the March 31, 2026 and June 30, 2026 quarters, Vanguard filed Form 13F-NT (a notice that its holdings are reported by other Vanguard reporting managers instead) under CIK 0000102909, so no more current Vanguard-filed share count was available; this mirrors the same pattern already documented for Broadcom and Union Pacific.
• Register percentages use different share-count denominators depending on each holder's as_of date, per CSX's own filings: 1,859,740,714 shares outstanding at December 31, 2025 (FY2025 10-K, used for Vanguard's Q4 2025 13F row), 1,852,474,917 shares outstanding at June 30, 2026 (Q2 FY2026 10-Q cover page, used for all other institutional 13F rows and as company.shares_outstanding), and 1,860,734,684 shares outstanding at March 1, 2026 (the 2026 proxy's own beneficial-ownership-table denominator, used for the insider rows).
• Market capitalization ($92.91 billion as of August 17, 2026) is from stockanalysis.com, an aggregator, not a filing; recorded for reference only and not used as a basis for any holding or register figure.
• Insider rows overlap. The 'all directors and current executive officers as a group (total of 20)' row (5,512,003 shares, under 1 percent) contains the individually listed Angel and Hilal rows above and must not be added to them.