Honeywell
The industrial conglomerate whose internal quantum program became Quantinuum. Per the May 2026 S-1 filing, Honeywell retains approximately 54% of Quantinuum common stock.
Honeywell built one of the world's most sophisticated trapped-ion quantum computing programs inside its corporate research arm, drawing directly on the Nobel Prize-winning work of David Wineland at NIST Boulder. In 2021, that program was spun out and merged with Cambridge Quantum Computing to form Quantinuum, headquartered in Broomfield, Colorado.
Honeywell has remained the controlling shareholder of Quantinuum across multiple funding rounds. In September 2025, Honeywell announced a $600M capital raise target at a $10B pre-money valuation; the Series B closed oversubscribed at approximately $800M on November 5, 2025. Quantinuum's S-1 filing reports Honeywell as holding approximately 54% of common stock as of December 31, 2025.
The Quantinuum stake makes Honeywell the largest corporate beneficiary of Colorado's trapped-ion research lineage, and one of the most concentrated single bets on quantum computing by a public industrial company.