New York, February 27, 2026, 16:21 EST — After-hours
- SNDK dropped 2.5% during regular trading, then slipped an additional 0.4% in after-hours action
- SK hynix and Sandisk kicked off an Open Compute Project workstream aimed at setting standards for “High Bandwidth Flash.”
- A director has filed to unload 3,500 shares through SEC Rule 144.
Sandisk Corporation (SNDK) lost ground Friday and slipped further after hours, as the market digested its latest AI-memory initiative and eyed potential stock sales. Shares dropped 2.5% to finish at $635.31, then edged down another 0.4% post-close to $632.70. The day’s range: $621.27 to $661.20. The Nasdaq Composite shed about 0.9%. Micron Technology declined 0.8%, while Western Digital gave up 0.9%. 1
This is significant: Sandisk’s stock, a packed trade in the tight memory sector, has squeezed both new buyers and short sellers over even minor news. Given the rally, filings or product buzz now quickly ripple through the price.
Looking ahead to next week, it boils down to this: will the company maintain the AI momentum without triggering another supply jolt. Pricing power in NAND flash—the memory Sandisk deals in—has a way of reacting fast; even a whiff of weakness here and sellers don’t wait around.
SK hynix said Thursday it’s teaming up with Sandisk to start a joint workstream under the Open Compute Project, aiming to set a standard for “High Bandwidth Flash” (HBF). The technology is meant to sit between high-bandwidth memory that sits close to AI chips and conventional solid-state drives. Their pitch: HBF could help boost scalability and lower power use when running AI models in production. “By making HBF an industry standard … we will lay the foundation for the entire AI ecosystem to grow together,” SK hynix said. The company also pointed to industry forecasts suggesting more demand for advanced memory solutions like HBF could emerge around 2030. 2
Sandisk director Miyuki Suzuki is looking to offload 3,500 shares, a chunk valued around $2.20 million, according to a regulatory filing. The planned sale, routed via Morgan Stanley Smith Barney, was disclosed with a Form 144—required by SEC rules when insiders intend to unload restricted stock. 3
Andrew Left at Citron Research is taking the short view, saying the company’s valuation is out of step—being treated like an AI heavyweight instead of a commodity name. “The market is pricing SanDisk like it’s $NVDA,” Left posted on X. He warned, “memory is a cycle, and cycles peak,” flagging Samsung as the stronger threat on the competitive front. 4
The way Sandisk is set up keeps the supply narrative in play. According to a prospectus supplement, Western Digital spun off 80.1% of Sandisk, with the deal taking effect Feb. 21, 2025, and Sandisk stock debuting for regular-way trading on Nasdaq three days later, Feb. 24, 2025. As of Feb. 6, Western Digital still held about 5.1% of Sandisk and has filed to resell as many as 7.51 million shares. Sandisk lists its shares outstanding at roughly 147.6 million. 5
Even so, HBF’s move remains preliminary—setting standards doesn’t translate to immediate orders. A sudden shift in memory prices, or if bigger players ramp up supply quicker than anticipated, could expose just how much Sandisk’s valuation is riding on the narrative of an imminent shortage.
Come Monday, U.S. markets are back in action. Sandisk faces a test out of the gate—will momentum buyers stick around for the opening stretch? Eyes shift next to the company’s earnings report, set for May 13. 6
