What is CXMT's 'Chinese chip bomb' that has wiped billions off the US stock market

China's CXMT has sent global memory chip stocks tumbling after claiming key progress on a denser 4F² DRAM design and plans for a server memory module by the end of 2026. Micron, SK Hynix and Samsung have lost billions in market value as investors question how long AI-driven memory profits can last. Here is what CXMT announced, why it matters and what analysts make of the threat.