This AI Memory Stock Is Up More Than 650% in 2026. Micron Investors Should Pay Attention

SanDisk Corporation (NASDAQ:SNDK) has experienced an exceptional year-to-date performance, surging more than 650% since September 18. This remarkable growth has catapulted the memory manufacturer into the S&P 500's top performers. Micron Technology, Inc. (NASDAQ:MU), also facing an AI-memory shortage, has seen similar gains, but SanDisk's surge stands out.

The catalyst for this stock's meteoric rise remains unclear, as no single event could explain it. Investors are now questioning whether SanDisk's stock is adjusting to tighter storage demand or if momentum has overtaken the underlying improvements. The core demand for SanDisk's products lies in AI systems, which generate extensive data, model checkpoints, and inference content, necessitating NAND flash and enterprise storage.

The company's fiscal fourth-quarter revenue climbed 51% sequentially to $8.97 billion, while datacenter revenue more than doubled. SanDisk's entry into the S&P 100 on September 21 further fueled its momentum. However, the valuation of the stock raises concerns, as a 655% year-to-date gain suggests investors are paying for more than just recovery.

SanDisk now faces the challenge of maintaining sustained pricing, volume, and margins, given the radically changed expectations. In contrast, Micron Technology, Inc. offers a more diversified AI-memory position, including DRAM, HBM, and NAND, but also exposes the company to cyclical risks if new capacity emerges. Insider Monkey's database revealed that 128 hedge funds held SanDisk in Q2, up from 114 in Q1, while Micron's fund holder count jumped even more sharply, to 184 funds from 154.

Coatue Management increased its Micron position by approximately 1,794% during the quarter. Despite the AI-memory trade's fundamental support, the critical question remains: how much support the price already assumes after the 655% gain. While both SanDisk and Micron present intriguing investment opportunities, other AI stocks may offer greater upside potential with lower downside risk.