SanDisk Corp. shares plunged 5.37% in after-hours trading on Wednesday, as a weaker-than-expected revenue outlook for the upcoming quarter overshadowed the company's strong fiscal fourth-quarter results. The memory maker delivered earnings and revenue that surpassed analyst estimates, but investors focused on the forward guidance miss.

The company reported adjusted earnings of $39.25 per share on revenue of $8.97 billion for the fiscal Q4, both exceeding Wall Street's consensus. However, SanDisk's guidance for the fiscal first quarter projected revenue between $10.3 billion and $10.8 billion, which fell short of the analyst estimate of $10.82 billion. This slight miss in the revenue outlook, combined with already elevated pre-earnings expectations, triggered a sell-off in extended trading.

The post-market decline highlights market concerns that even a robust past performance could not fully offset a cautious near-term forecast, amid ongoing anxiety over the sustainability of the AI-driven memory demand cycle. Despite the company announcing a $14 billion expansion of its share buyback program, the disappointing guidance dominated investor sentiment and drove the after-hours plunge.