Citadel Advisors discloses new Q2 stakes in SpaceX, Cerebras Systems, and Quantinuum

Citadel Advisors just handed the market a glimpse of where one of the world’s most powerful hedge funds is placing its chips. The firm’s Q2 2026 13F filing reveals new positions in SpaceX, Cerebras Systems, and Quantinuum, three companies operating at the intersection of aerospace, advanced AI hardware, and quantum computing. The bigger headline buried inside that filing: Citadel’s equity portfolio ballooned to $875.1 billion, up 41.5% from the $618.5 billion it reported in Q1 2026. That’s $256 billion in new equity exposure added in a single quarter. Three bets, three frontier sectors Cerebras Systems raised $1 billion in a Series H funding round led by Tiger Global in February 2026, a round that pegged its post-money valuation at roughly $23 billion. By June 2026, Cerebras had gone public on the Nasdaq under the ticker CBRS, raising $6.4 billion in what became one of the more closely watched tech IPOs of the year. Citadel’s Q2 filing captures positions as of the end of the quarter, meaning its Cerebras stake likely reflects shares acquired either before or around the IPO window. The exact entry price and position size have not been disclosed in the filing. Quantinuum reached a pr...