• The US Department of Defense spent about $320 million on quantum research in FY2023.
• Disclosed defence contracts came to $114 million to $141 million a year from 2023 to 2025.
• Paid market reports put 2024 between about $0.2 billion and $1.9 billion.
• The largest disclosed award outside computing is IonQ's $55 million Air Force contract.

The quantum defence sector's size may indicate a growing interest in quantum technology for military applications, which could suggest a shift in defence priorities. The significant difference in estimates between market reports may indicate a lack of transparency or inconsistent definitions, which could impact investment decisions. The sector's growth may be driven by government funding, which could create opportunities for companies involved in quantum research and development.