Atlassian shares are rising sharply in Thursday’s session (April 16, 2026) as event-driven investors trade around the company’s pending removal from the Nasdaq-100. The index change is scheduled to take effect prior to market open on Monday, April 20, 2026, with Sandisk set to replace Atlassian, creating a near-term catalyst for repositioning, hedging activity, and fast money flows.

Nasdaq-100 membership can influence demand from index-tracking funds and derivatives-linked strategies. With Atlassian slated to exit the benchmark, some holders may be adjusting exposure early (or buying back hedges), while other participants attempt to front-run or fade the expected rebalance-related flows around the effective date. This kind of setup can produce sharp, temporary price moves that don’t necessarily reflect a change in the company’s fundamentals.

The key dates are the rebalance effective open on April 20, 2026 and Atlassian’s next scheduled earnings report on April 30, 2026. Investors will be watching for updates on growth, cloud momentum, and the cost structure after the company’s recently announced workforce reduction tied to an AI and enterprise-sales pivot, including the expected restructuring charges disclosed for that plan.