Global stocks face Q4 earnings test as rich valuations and sector risks threaten volatility

Global equity markets are trading at elevated valuations, with the MSCI World Index at 20 times forward earnings while Q4 results start to roll in. Investors are relying on strong profit growth from AI leaders, banks, consumer goods firms, and defense contractors to justify last year's rally and avoid renewed volatility. At the same time, shifting tariffs, oil supply threats, and surging defense spending are adding fresh uncertainty across regions.