Micron Technology (NASDAQ:MU) experienced a sharp decline on Monday, with shares falling 5.3% to $927.10 by early afternoon, after briefly touching a low of $902.64—a drop of 7.8%. The selloff erased approximately $59.8 billion in equity value from Friday's close, as a broader semiconductor downturn that began in Asian trading spilled over into U.S. markets.
The Philadelphia Semiconductor Index slid 3.7% and sat more than 14% below its late-June record by midday. While the market's reaction does not signal a collapse in demand for AI memory chips, it does reflect a recalibration of the premium investors are willing to pay for profits generated during a supply shortage. "We've never seen this kind of extreme earnings growth," noted Steve Sosnick, chief market analyst at Interactive Brokers, highlighting the uncertainty around how long such elevated margins can persist.
Record Margins Under the Microscope
Micron's fiscal third-quarter non-GAAP gross margin—the portion of revenue left after direct production costs, excluding certain accounting items—soared to 84.9%, up from 74.9% in the prior quarter and 39% a year earlier. The company has guided for fiscal fourth-quarter revenue of approximately $50 billion and a margin near 86%. At that revenue level, each 10-percentage-point change in margin equates to roughly $5 billion in quarterly gross profit before operating expenses and taxes.
On a headline earnings basis, the stock appears cheap. According to Zacks, Micron's forward price-to-earnings ratio stands at 13.43 times, compared to 27.73 for the industry—a 52% discount. However, other valuation metrics tell a different story. The price-to-sales ratio of 12.41 reflects a 24% premium over the industry average of 10.00, while the price-to-book ratio of 11.12 represents a 32% premium over the industry's 8.40. This split underscores the central investor dilemma: Micron is inexpensive only when measured against its exceptional profit margins, but investors are already paying premiums for each dollar of sales and net assets.
Competitive Landscape and Expansion Plans
The high-bandwidth memory (HBM) market remains concentrated. SK Hynix (NASDAQ:SKHY) captured 58% of first-quarter HBM revenue, while Micron and Samsung Electronics each held 21%. SK Hynix's American depositary receipts fell 7.9% in early Monday trading, indicating the pressure was not isolated to Micron. Both SK Hynix and Samsung have announced 400 trillion won in chip-plant investments in South Korea, while Micron has raised its planned U.S. investment to more than $250 billion through 2035. First output from two Idaho plants is expected in mid-2027 and late 2028, respectively.
Analysts remain divided on whether these new facilities will alleviate the shortage or merely chase demand. Bernstein analyst Mark Newman suggested that memory multiples are "pricing an imminent collapse in profits," while D.A. Davidson analyst Gil Luria countered, "We can't possibly have enough of it."
Risks and Outlook
The downside could materialize before the new factories come online. A slowdown in AI infrastructure spending, weaker-than-expected HBM adoption, or a rise in conventional memory output could pressure prices while Micron continues to fund its expansion. Conversely, if demand keeps outpacing capacity, margins could remain elevated, and long-term contracts may reduce the typical memory-cycle volatility. In that scenario, Monday's selloff could prove to be a valuation reset rather than the start of an earnings downturn.
For investors, the key metric is no longer Micron's forward P/E alone. It is the durability of the roughly 86% margin embedded in the company's near-term outlook. Every 10-point movement in margin is worth about $5 billion in quarterly gross profit at guided revenue—enough to explain why a supply forecast years into the future can strip nearly $60 billion of market value in a single session.
