SanDisk Shares Sink 5.18% as DeepSeek's Leaner AI Model Rattles Memory Chip Stocks Worldwide Once Again

SAN JOSE, Calif. — Shares of SanDisk Corp. fell 5.18% to $1,544.98 in Monday trading, down $84.59, as a fresh wave of concern over the pace of artificial intelligence development combined with lingering questions about a Chinese AI model's dramatically reduced memory requirements to pressure NAND flash and memory chip stocks across the board.

The decline, which briefly pushed shares down as much as 6% in premarket trading before paring slightly at the open, extended a broader pullback for storage and memory names Monday. Micron Technology fell roughly 5%, while Western Digital and Seagate Technology each dropped more than 4%. South Korea's SK Hynix fell more than 7% in its own session. The sector-wide weakness came as investors weighed calls from prominent AI executives to slow the pace of frontier model development against a separate, more technical concern specific to memory chipmakers: whether the assumptions underpinning the sector's explosive rally may be overstated.

That second concern traces back to DeepSeek, the Chinese AI developer, which released an updated version of its cost-optimized Flash model on September 10. The new model, DeepSeek V4.1 Flash, introduced architectural changes that dramatically reduce the amount of memory needed to run AI inference workloads, cutting the model's key-value cache consumption, a core driver of memory demand during AI processing, to between roughly 13% and 25% of its predecessor's requirements. In practical terms, the redesign allows the model to support four to eight times as many simultaneous users within the same memory footprint, according to DeepSeek's own technical documentation.

The release rattled memory chip investors because so much of the sector's recent rally has been built on the assumption that AI inference workloads would require ever-increasing amounts of high-bandwidth memory and NAND flash storage as AI adoption scales. If leading AI model developers adopt similar memory-efficient architectural techniques broadly, some analysts have warned, the baseline demand growth for high-capacity enterprise storage and memory chips, the very products that helped drive SanDisk's revenue to $20.25 billion in its most recent fiscal year, could plateau earlier than current Wall Street forecasts anticipate. The concern first hit Samsung Electronics and SK Hynix directly in Seoul trading on September 11, when the DeepSeek release sent both stocks lower, before spreading more broadly across the global memory sector as U.S. markets absorbed the news alongside the weekend's separate AI safety debate.

That AI safety debate, triggered by a weekend essay from Anthropic Chief Executive Officer Dario Amodei calling for a coordinated industry-wide slowdown in AI capability development, added a second, distinct source of pressure on memory stocks Monday, compounding the DeepSeek-related unease. Not every investor has accepted the safety framing at face value, however. Prominent short-seller Michael Burry, known for his early bet against the U.S. housing market, publicly dismissed the slowdown calls as self-interested positioning. "Let's all take a moment to understand how self-serving it is for OpenAI, Anthropic and other execs of big hyperscalers to talk of slowing things down," Burry wrote on social platform X, adding that large language models are not, in his view, genuine artificial intelligence and therefore have "nothing AI to slow down." He also suggested the safety rhetoric could serve as convenient cover for both companies as they prepare for stock market listings, writing separately, "IPOs need hype & puffery."

Despite Monday's sharp decline, SanDisk's rally over the past year has been extraordinary by almost any measure. The stock's 52-week range spans from a low of roughly $82 to a high of $2,354.39, reflecting a period of intense investor enthusiasm for memory chip stocks tied to the broader AI infrastructure buildout. Even after Monday's drop and a broader pullback that has already seen shares fall roughly 31% from their year-to-date high, SanDisk remains up dramatically from where it traded a year ago.

Wall Street's outlook on the stock has remained largely positive even amid the recent volatility. Among 24 analysts covering the stock, the average rating remains a Buy, with a 12-month consensus price target of $2,125.09, implying substantial potential upside from current levels. Individual analyst targets have varied in recent weeks: Mizuho maintained an Outperform rating while trimming its price target to $1,875 in late August, RBC Capital raised its target to $1,600 while maintaining a more neutral Sector Perform rating, and Wells Fargo lifted its own target to $1,550 while keeping an Equal-Weight stance, reflecting a range of views on how much further the stock can climb even as most analysts remain constructive on the underlying business.

The bull case for SanDisk and its memory sector peers has rested heavily on severe supply constraints in the broader chip market. Industry researcher TrendForce has projected conventional DRAM contract prices to rise sharply quarter over quarter through the first half of 2026, with NAND flash contract prices also climbing substantially over the same period, reflecting a market where supply has struggled to keep pace with demand. Samsung's chief financial officer has said the company's 2026 production of next-generation HBM4 memory chips is already fully sold out, underscoring how tight the supply picture has been even before DeepSeek's efficiency breakthrough raised questions about the durability of that demand.

Whether DeepSeek's memory-efficient architecture proves to be an isolated technical achievement or the start of a broader industry shift toward less memory-intensive AI model design remains an open question for investors. Some engineers who have examined the model's architecture note that while its reduced live memory footprint is significant for serving AI inference at scale, it does not directly reduce the massive amount of memory still required to train large AI models in the first place, suggesting the long-term implications for chip demand may be more nuanced than Monday's sharp selloff implies.

With SanDisk's stock remaining highly sensitive to shifting sentiment around AI infrastructure demand, and with the broader debate over the pace of AI development still unfolding following Amodei's essay, investors are likely to remain focused in the coming days on further signals from both the AI industry's largest developers and its chip suppliers about how durable current memory demand assumptions actually are.