SanDisk (SNDK) vs. Seagate (STX): Which Storage Stock Is the Better Buy Right Now?

The AI trade is moving beyond GPUs. As AI models become more capable, they also generate, process, and retain massive amounts of data. That is creating a less glamorous but increasingly important question for data centers: where does all that data go?

SanDisk Corporation (NASDAQ: SNDK ) and Seagate Technology Holdings plc (NASDAQ: STX ) offer two very different answers. SanDisk is benefiting from growing demand for NAND flash and enterprise SSDs, while Seagate is betting that the sheer volume of AI-generated data will keep driving demand for high-capacity hard drives.

Both have strong AI tailwinds. But the stocks are telling very different stories.

SanDisk is riding a changing storage mix

SanDisk Corporation (NASDAQ:SNDK)'s biggest opportunity is that AI inference is making storage more important. CEO David Goeckeler described AI as a "memory-centric, storage-intensive problem," with every interaction creating data that needs to be stored, retrieved, and served quickly. Data center already accounted for 38% of SanDisk's portfolio at the end of fiscal 2026, up from roughly 12% a year earlier.

The company is also trying to make its earnings less dependent on the notoriously volatile NAND cycle. SanDisk now has eight long-term business agreements with customers, with a weighted average duration of more than four years. Management expects these contracts to cover more than half of its fiscal 2027 bits and roughly two-thirds in fiscal 2028.

That matters because SanDisk isn't simply hoping AI demand remains strong. It is increasingly locking in customers and supply commitments ahead of time.

Seagate is making the case for hard drives

Seagate's opportunity is different. AI does not just require fast storage. It creates huge amounts of data that companies need to keep.

CEO Dave Mosley argued that AI is causing data to compound because companies are retaining more information for historical context, compliance, and future reuse. Seagate also sees newer workloads such as agentic AI and physical AI creating additional storage demand.

That is important because hard drives remain the mass-storage layer in many data centers. Seagate's data center business now represents about 90% of its exabyte shipments, and its long-term supply agreements have already allocated the vast majority of nearline capacity into 2028.