Micron's September 30 Earnings Arrive Amid Short Pressure and Samsung HBM Competition

Key Takeaways

• Micron and SanDisk shares dropped 1.5% to 2% in premarket Thursday, a second consecutive day of declines after sharp multi-week rallies.
• Michael Burry disclosed a sizeable short position in Micron, arguing that memory-chip valuations have outpaced fundamentals and face cyclical risk.
• Samsung has earmarked more than half of its 4nm foundry capacity for HBM4 base-die production, intensifying competition in high-bandwidth memory.
• Micron has guided for $50 billion in revenue and roughly 86% gross margin for fiscal Q4, while Wall Street consensus sits at $51.2 billion in revenue.

Shares of Micron Technology (MU) and SanDisk (SNDK) fell 1.5% to 2% in premarket trading Thursday, extending a two-day slide as profit-taking interrupted a multi-week memory rally. The pullback coincides with short-seller Michael Burry revealing a large short position in Micron and Samsung ramping HBM4 production capacity, setting a charged backdrop for Micron's fiscal fourth-quarter report on September 30.

Numbers at a Glance

Micron Revenue Guidance (FQ4)

$50 billion

Micron's own guidance figure for fiscal Q4, against which Wall Street's $51.2B estimate represents a modest premium.

Wall Street Revenue Estimate (FQ4)

$51.2 billion

Consensus estimate implies 353% year-over-year revenue growth, per Koyfin data cited in the source.

Micron Gross Margin Guidance

~86%

Company-guided gross margin for fiscal Q4, reflecting the pricing environment for DRAM, NAND, and HBM.

SanDisk YTD Gain

665%

SanDisk's year-to-date share appreciation, underscoring how much gain is at risk during the current pullback.

Expectation Gap Between Company Guidance and Street Estimates

Micron has guided fiscal fourth-quarter revenue to $50 billion, yet Wall Street's consensus lands at $51.2 billion — a gap that creates a clear bar the company must clear to avoid a negative reaction even on strong results. The company also guided for an adjusted EPS of $31, while analyst estimates project adjusted EPS of just $0.53, a striking divergence that likely reflects different accounting treatments or fiscal-year conventions rather than a straightforward disagreement about profitability.

The gross margin guidance of approximately 86% is the figure most directly tied to memory pricing power. Because DRAM and NAND prices fluctuate with supply-demand cycles, any commentary on pricing trajectory for fiscal 2027 may matter more to investors than the headline revenue number itself.

Two External Forces Compressing the Rally

The two-day pullback appears driven by factors beyond ordinary profit-taking. Burry's disclosed short position carries weight because he argues memory valuations have run ahead of underlying fundamentals — a cyclical-downturn thesis that directly challenges the AI-driven demand narrative that propelled both MU and SNDK to outsized year-to-date gains of 276% and 665%, respectively.

On the competitive side, Samsung's (005930.KS) decision to dedicate more than half of its 4nm foundry capacity to HBM4 base-die production signals an aggressive push into the segment where Micron has been gaining ground with AI accelerator customers. HBM products have become a meaningful part of Micron's business as data-center operators scale AI infrastructure, so any shift in competitive dynamics there carries direct revenue implications. The combination of a prominent short thesis and a well-capitalized competitor accelerating in the same product category gives investors reason to reassess positions ahead of the earnings print.

InvestorStack Lens

The September 30 report functions as a real-time stress test for the AI memory thesis. If Micron's HBM demand commentary and fiscal 2027 pricing outlook remain strong, it would directly challenge Burry's cyclical-downturn argument. Conversely, any softness in forward guidance could validate concerns that valuations — built on triple-digit percentage YTD gains — have moved ahead of fundamentals. The EPS discrepancy between company guidance and consensus warrants scrutiny; clarity on which methodology is being compared would help investors assess the true earnings expectation gap.

What Could Challenge This View

The most credible pushback on the bearish case is that memory demand from AI infrastructure is described in the source as being at record levels. If Micron's results confirm that HBM pricing and volumes remain robust, both the Burry short thesis and Samsung competition concerns could prove premature — and the current two-day slide would more simply represent healthy consolidation after gains of 276% and 665% year to date.

What to Watch Next

• Micron's fiscal Q4 revenue versus both its own $50 billion guidance and the $51.2 billion Wall Street consensus on September 30.
• Management commentary on HBM demand trajectory and memory pricing into fiscal 2027.
• Any update on Micron's HBM market share in light of Samsung's accelerated 4nm HBM4 capacity build.
• Whether Burry's short position size changes materially following the earnings report.
• SanDisk's price reaction to Micron results, given its 665% YTD gain leaves it exposed to sentiment shifts in memory stocks.