Sandisk shares are up today as traders position for the company’s upcoming addition to the Nasdaq-100 Index. Nasdaq announced Sandisk will become a Nasdaq-100 component prior to market open on Monday, April 20, 2026, replacing Atlassian, putting SNDK in the crosshairs of index-linked demand and event-driven flows.

Nasdaq-100 inclusion is a mechanical catalyst: index funds and ETFs that track the Nasdaq-100 (and related benchmarks/derivatives) typically need to rebalance by buying the new constituent and selling the removed name. That forced, time-bound demand can lift shares into the effective date, and it can also increase near-term volatility as hedge funds and options desks crowd around the rebalance window.

The key near-term marker is the inclusion effective date (April 20, 2026), when final index-rebalance activity typically concentrates. The next fundamental catalyst on the calendar is Sandisk’s fiscal third-quarter earnings release and conference call on April 30, 2026, which could either validate the run-up or reset expectations depending on guidance and memory-market commentary.