US stock market volatility surged as US-Canada trade tensions rattled investors. The Dow Jones dipped 0.3%, while the S&P 500 fell 0.3%, reversing earlier gains. Despite a 3.1% rise in core CPI, marking its lowest increase since April 2021, tariff concerns overshadowed inflation relief. Canada retaliated with $21 billion in duties on US goods, following Trump's steel and aluminum tariffs. The EU also imposed $28 billion in counter-tariffs. While Nvidia (NVDA) and Tesla (TSLA) surged over 4%, other sectors suffered.