Editor's Introduction for the 2026 Special Issue on Multi-Asset Strategies and Asset Allocation.

This special issue focuses on structural sources of fragility in multi-asset strategies and asset allocation, emphasizing challenges such as regime dependence, estimation risk, correlation instability, diversification limits, and governance constraints. It combines practitioner interviews from diverse institutional investors with analytical articles that explore regime-aware portfolio construction, the limits of optimization, and the dynamic role of bonds and risk premiums across market environments. The issue highlights that many difficulties in multi-asset portfolio management stem from embedded assumptions and institutional realities rather than execution errors, advocating for approaches that balance robustness, adaptability, and governance over reliance on precise quantitative models. Together, the interviews and articles provide a comprehensive view of how multi-asset frameworks function under uncertainty and evolving market conditions in institutional settings. [Extracted from the article]