In early September 2026, SanDisk crossed a threshold that markets treat as a rite of passage — entry into the S&P 100 — sending its shares nearly 12 percent higher as institutional capital rushed to realign. The move speaks to something larger than one company's fortunes: it reflects a market beginning to believe that the volatile memory chip sector may have found steadier ground, buoyed by demand from data centers and artificial intelligence. Whether that belief proves durable or premature is the question the next three weeks will quietly answer.