Portfolio Companies 2026 for Sam Altman: investors, rounds, and co-investor patterns from StartupFundraising.com research, updated for 2026.
Sam Altman accounts for 11 tracked companies with verified cap-table data, 11 of which disclose round sizes totalling $1.2B. The median disclosed raise is $100M, and the largest is Rescale at $200M, ahead of Retro Biosciences ($180M) and Exowatt ($140M).
The names that recur most often on these portfolio cap tables are Sam Altman (11 companies), Lachy Groom (2 companies), Jeff Bezos (1 company), Peter Thiel (1 company), Paul Graham (1 company), Nvidia (1 company). By latest disclosed round, the market skews Series A (4), Series C (2), Series B (2), Series D (1).