Market concentration risks emerge as USD/JPY tests 156.80 resistance

USD/JPY has climbed 0.2% to 156.80 as risk appetite returns to markets, but analysts warn of growing concentration risks in equity indices. The S&P 500 ETF (SPY) gained 1.2% despite concerns that market breadth remains narrow, with top-heavy positioning potentially vulnerable to corrections. EUR/USD advanced 0.3% to 1.0845 as the dollar weakened broadly following easing geopolitical tensions. The lack of broad market participation raises questions about sustainability of the current rally, with only a handful of mega-cap stocks driving index gains. Technical indicators show USD/JPY approaching key resistance at 157.00, which has capped advances three times this month. A break above could target 157.50, while failure might see a pullback to 156.20 support. Traders should monitor market breadth indicators closely, as deteriorating internals could signal an impending correction despite positive headline figures.