Key Highlights

● SNDK shares slipped 0.92% to $1,704.16 on Monday, October 5, on 6.5 million shares, about 0.79 times normal volume.

● Fiscal fourth-quarter Revenue reached $8.97 billion, up 372% from a year earlier, with gross Margin of 84.6% and non-GAAP Earnings of $39.25 per share.

● Fiscal first-quarter 2027 guidance calls for revenue of $10.3 billion to $10.8 billion and non-GAAP EPS of $44 to $46.

● Management cited ten new long-term agreements with eight strategic customers that it says provide minimum revenue of $93.9 billion at floor prices.

What put Sandisk (NASDAQ:SNDK) ninth on Monday's list of most actively traded US stocks was arithmetic more than news. The flash-memory maker slipped 0.92% to $1,704.16 on 6.5 million shares, below its normal Volume at 0.79 times average, according to market data. But with a share price above $1,700, even an ordinary session moves a lot of money: about $11.1 billion of Sandisk stock changed hands, more than Twilio (NYSE:TWLO), Amazon (NASDAQ:AMZN) or Intel (NASDAQ:INTC).

What's driving the volume

There was no company-specific headline on Monday. Instead, Sandisk drifted with a memory complex that split in two directions. Micron (NASDAQ:MU), the largest US memory maker, fell 1.02%, while hard-drive makers Western Digital (NASDAQ:WDC) and Seagate (NASDAQ:STX) rallied 6.34% and 4.49%, respectively. The broader market was firm, with the Nasdaq Composite up 1.05% as softer jobs data reduced expectations for more Fed rate hikes, even though the 10-year Treasury Yield rose to 5.31%, its highest level since 2002.

The past week has been a tug of war for the stock. On September 28, Sandisk fell 3.9% after OpenAI said it would pause Training on some AI models to investigate reports of malfunctioning agents, a reminder of how closely memory stocks track sentiment around AI spending. Then Micron's fiscal fourth-quarter report on September 30 shifted the mood back. Citi (NYSE:C) analyst Atif Malik noted that Micron's NAND revenue jumped 42% sequentially as prices rose about 30%, well ahead of the roughly 20% the market expected, and argued that tight NAND Supply could last into 2027 and 2028.

Citi reiterated its Buy rating and $2,100 target on Sandisk, and the shares rose more than 2% on October 1. Memory names gave back some ground on October 2, and Monday continued the consolidation. Context matters here: at the start of October the shares were up more than 530% for the year and more than 1,300% over 12 months, so modest daily declines are pauses in a historic run rather than signs of distress. Technical commentary on Monday framed the stock as sitting near support around $1,720, below resistance near $1,893.

The business

Sandisk designs and manufactures NAND flash memory and the products built on it, from solid-state drives for data centers and PCs to memory cards and USB drives for consumers. It was spun out of Western Digital in February 2025, leaving Western Digital with its hard-drive business. Sandisk joined the S&P 500 in November 2025 and the Nasdaq-100 in April 2026, and FTSE Russell moved it into its large-cap growth indexes at the June 2026 reconstitution.

The AI build-out has transformed the company. Data centers need enormous amounts of fast storage to feed and serve AI models, and Sandisk's management has argued that AI is fundamentally a memory-centric, storage-intensive problem. Datacenter revenue now accounts for about 38% of sales, up from roughly 12% a year earlier.

Recent results and guidance

The numbers are extraordinary even by semiconductor standards. For fiscal fourth quarter 2026, reported August 5, revenue reached $8.97 billion, up 51% from the prior quarter and 372% from a year earlier, with about two-thirds of the increase coming from higher prices. Gross margin was 84.6% and non-GAAP earnings were $39.25 per share, beating consensus estimates of about $34.59. Datacenter revenue more than doubled sequentially to $2.98 billion. For the full fiscal year, revenue rose 175% to $20.25 billion and GAAP Net Income was $11.43 billion.

Guidance for fiscal first quarter 2027 calls for revenue of $10.3 billion to $10.8 billion, gross margin of 83% to 84.9% and non-GAAP EPS of $44 to $46. Management also highlighted ten new long-term agreements with eight strategic customers that it says provide more than four years of visibility and minimum revenue of $93.9 billion at floor prices. Even so, the stock fell about 12% across the regular and after-hours sessions after that report, as investors weighed how much good news was already priced in.

Management's supply commentary matters as much as the headline figures. The company said Capital spending will rise to support its BiCS8 and BiCS10 technology nodes while staying near 6% of revenue, and it expects industry bit growth in the mid- to high-teens in 2027, slightly below historical norms. Disciplined supply is the main reason prices have kept rising, and the CFO said the long-term agreements should produce attractive margins even at floor pricing.

Valuation

Sandisk's trailing P/E of 23.38 is above Micron's 14.34 and Western Digital's 18.27, but well below Seagate's 63.94. Forward multiples tell a different story: the forward P/E is about 8, reflecting expectations that earnings keep climbing as fiscal first-quarter guidance alone implies EPS of $44 to $46 in a single quarter. The consensus price target is about $2,137. The 52-week range, from roughly $116 to $2,354, shows how violent the move has been, and the stock remains well below that peak. At a Market Value of $249.52 billion, Sandisk is now worth considerably more than both Seagate, at $201.72 billion, and Western Digital, its former parent, at $159.23 billion.

Bull case

● NAND pricing is still rising, and Micron's results suggest supply stays tight for at least another year or two.

● Long-term agreements with floor pricing could dampen the classic memory boom-bust cycle.

● On forward earnings, the stock looks inexpensive relative to the tech sector.

Bear case

● Memory has historically been deeply cyclical, and margins near 85% invite new supply and eventually lower prices.

● Two-thirds of recent growth came from price, which can reverse faster than volume.

● The stock is highly sensitive to any sign of slower AI spending, as the OpenAI-related selloff showed, and to rising interest rates.

Sandisk's October 29 report and the NAND pricing test

The next major catalyst is Sandisk's fiscal first-quarter 2027 report, scheduled for October 29. Investors will focus on whether revenue lands at or above the $10.3 billion to $10.8 billion range, whether gross margin holds above 83%, and how much more of the company's output gets locked into long-term agreements. Beyond Sandisk itself, NAND contract-price data, capital-spending plans from rivals and hyperscaler commentary on AI infrastructure budgets will continue to drive the stock. With Treasury yields at multi-decade highs, macro data also matters more than usual for richly rewarded growth names like this one.