US stocks rebounded in May, posting the first monthly gain since January. The strong recovery lifted American shares to the top of the leaderboard for the major asset classes last month, based on a set of ETFs.
The Global Market Index (NYSE:) rallied 6.3%, leading a widespread rally in global assets. The gain marks the best monthly advance for US stocks since Nov. 2023.
Most of the world’s markets rose in May. The downside outliers: bonds in developed markets. The biggest setback: US bonds (), which shed 0.7%, the first monthly decline this year.
Year to date, stocks in developed markets ex-US () continued to lead, rising nearly 17% in 2025. The weakest year-to-date performer for the major asset classes: a broad measure of commodities (GSG) with a 2.8% decline in 2025. Otherwise, the remainder of the major asset classes are posting gains.
The Global Market Index (GMI) continued to recover in May, posting a strong 4.7% advance — the best monthly gain in a year-and-a-half. For the year so far, GMI is up 4.2%.
GMI is an unmanaged benchmark (maintained by CapitalSpectator.com) that holds all the major asset classes (except cash) in market-value weights via ETFs and represents a competitive benchmark for multi-asset-class portfolio strategies.