HedgeCo.Net — D1 Capital Partners L.P. filed a 13F-HR on August 14 covering the quarter ended June 30, 2026. The information table lists 55 long U.S. equity positions with an aggregate reported value of about $34.78 billion. Space Exploration Technologies, reported as Class A common, is 126,042,232 shares valued at $21,535,575,760 — 61.9% of that disclosed book. Hedgeweek, citing Institutional Investor, put the same stake at more than $21.5 billion and more than 126 million shares, about 61% of D1’s U.S. common-stock holdings. That is a 13F weight. It is not firm assets under management.
The next disclosed line is far smaller. Maplebear (Instacart) is 22,564,435 shares valued at $1,068,425,997, or 3.1% of the reported total. James Hardie, Nu Holdings, and Johnson Controls follow. Sole voting and dispositive authority sits on the SpaceX line. A 13F reports long U.S. listed equity. It does not show shorts, derivatives, or any remaining private book. SpaceX began trading in June 2026, so this is a first public-table print of a position D1 had carried privately.
Hedgeweek’s Institutional Investor report called D1 the largest hedge-fund holder and the company’s 10th-largest shareholder overall. Those ranking claims sit in that write-up, not in the SEC table. The filing itself is a snapshot as of June 30, dated 45 days. It does not tell an allocator whether Sundheim bought, held, or trimmed after the IPO window. A crossover book that was 45% SpaceX in private, as that same report had it, becoming ~62% once the shares are 13F-reportable is a listing mechanic as much as a new trade.
For hedge-fund allocators the diligence is concentration, not the ticker. A 62% single-name weight in the disclosed equity sleeve is a professional risk budget. It is not a model for a pension’s public-equity overlay. The rest of the 55-name table is residual. Anyone mining D1 for a diversified long book is reading a SpaceX filing with a public-equity appendix.
The second-order read is what a 13F can and cannot say after a crossover IPO. The $21.5 billion is a June 30 mark on a newly listed name, not proof of aggressive second-quarter buying and not a statement about D1’s gross or net exposure. Do not treat $34.8 billion as the firm. Do not treat 62% as a buy ticket. The print is how large a pre-IPO conviction looks once it is forced onto a public table.