The traditional 60-40 stock-and-bond portfolio is failing investors as the Iran war drives fears of stagflation. Government bonds, typically a hedge against equity losses, are now moving in tandem with stocks as traders worry about inflation and slowing economic growth. This correlation breakdown means the usual rebalancing strategies between equities, bonds, and inflation-linked assets aren't providing protection.

Without the cushion of falling bond prices during stock market declines, investors face a dilemma. The typical policy response of aggressive interest rate cuts becomes unavailable if inflation spikes from higher oil prices. As Rajeev de Mello at Gama Asset Management notes, correlations have shifted so dramatically that traditional diversification is no longer working.

Some investors are turning to alternatives like Chinese assets, oil, and the dollar as havens. Buffer ETFs using options to cap losses while limiting gains have shown relative resilience, with the $8.6 billion FT Vest Laddered Buffer ETF down just 1.5% in March compared to a 3% slide in the S&P 500. The market disruption highlights how geopolitical conflicts can upend decades of investment wisdom.