iStock/Getty ImagesMemory chip stocks have been on a tear in 2026, boosted by huge demand from the AI boom.Sandisk, Micron, and Western Digital have seen gains well into the triple digits.AI-driven demand is outpacing supply, and Wall Street is still bullish even as the gains pile up.Memory chip stocks have emerged as the next big wave of the AI trade and investors are all in.AI is driving up demand for memory, sending the stocks of the companie…