Pretty much nobody saw it coming. Five months and nearly a 1,000% return later, it’s one of the craziest comeback stories on Wall Street, with Sandisk, a stodgy old memory card company, vaulting to the top of the S&P 500 and squarely into the center of the AI trade.Last August, memory chip analysts, vendors, researchers, and consultants gathered in Santa Clara, California, for their big annual conference. The vibe was far from frantic — 2025 had been a strong year, with prices steadily rising. B...