Micron Books a $54 Billion Quarter and Sells Most of Its 2027 HBM in Advance

Micron Technology reported $54.23 billion in revenue for its fiscal fourth quarter in an 8-K filed with the SEC on Sept. 30, 2026 ¹. A year earlier the same quarter brought in $11.32 billion. The quarter ended Sept. 3, and its Cloud Memory unit, the one that sells high bandwidth memory to every data center customer, took $16.28 billion of the total ¹⁶. Micron guided the current quarter to $61.5 billion, plus or minus $1.5 billion ¹. On the call, management said agreements now cover the vast majority of its calendar 2027 HBM bit supply ².

High bandwidth memory, or HBM, is DRAM stacked in towers and set beside an AI processor so data reaches the chip fast enough to keep it busy ⁵. So a memory filing is a count of one physical input to compute, paid for and shipped. The question for the ledger is how much of that $54 billion is more memory, and how much is the same memory at a higher price.

What Micron shipped in its fourth quarter

Start with the scale. Micron's fourth quarter alone took in more than its whole fiscal 2025, which closed at $37.38 billion ¹. Full-year revenue for fiscal 2026 reached $133.19 billion. Gross margin in the quarter hit 86.8 percent, up from 44.7 percent a year before ¹.

Four business units split the money. Core Data Center led at $18.0 billion, then Cloud Memory at $16.28 billion, Mobile and Client at $13.11 billion, and Automotive and Embedded at $6.82 billion ¹. Micron's 10-K defines Cloud Memory as the unit "focused on memory solutions for large hyperscale cloud customers, and HBM for all data center customers" ⁶. That unit grew 18 percent from the prior quarter and more than tripled from a year earlier ¹.

Sanjay Mehrotra, Micron's chairman and chief executive, put the results in the ledger's own vocabulary. "AI is becoming Super Intelligence (SI), and memory enhances this intelligence and the competitiveness of our customers' platforms," Mehrotra said in the filing ¹. "We are increasing our investments in technology, products and manufacturing to help drive SI forward with our customers, and our Strategic Customer Agreements provide added confidence in the durability of Micron's financial performance." Read the last clause closely. Durability is the investor's worry, and Mehrotra answers it with contracts, a promise that buyers have already signed for future supply.

Micron's four business units in the quarter ended Sept. 3

Compared

The data4 rows · sources

Unit: billion dollars

Item	Value	Source
Core Data Center	18	[1]
Cloud Memory includes HBM	16.28	[1] [6]
Mobile and Client	13.11	[1]
Automotive and Embedded	6.82	[1]

Most of the 2027 HBM is already sold

The contracts are the stronger evidence. "We have completed agreements for the vast majority of our calendar 2027 HBM bit supply with significant price increases year-over-year," Mehrotra told analysts on the Sept. 30 call ².

How tight is supply? Mehrotra gave the answer in one long sentence. "Even with additional industry DRAM clean room space plans with robust demand trends, including new upside requests from customers, we do not have line of sight to when supply and demand will return to balance," he said ². A cleanroom is the dust-controlled hall where wafers are made, and it takes years to build.

Money follows the halls. Capital spending ran $10.77 billion in the fourth quarter and $27.37 billion for the year ¹.

The case for the move

Mehrotra's case is that the buyers have spoken with signatures. An SEC filing records revenue already recognized, which means memory already delivered. A contract for most of next year's HBM means accelerator makers have reserved the bits their 2027 chips will need. That is the kind of evidence the method calls confirmed: a filing, and chips delivered.

Independent analysts read the same numbers as strength. Patrick Moorhead, chief executive of Moor Insights & Strategy, called the results "Not a slowdown" in a post, pointing to the share of 2027 output already committed ⁴. Ben Bajarin, chief executive of Creative Strategies, aimed at the market's mood after the margin guidance. "The irony should not be lost on us that the memories industry has averaged single digit margins and folks are mad its not going to 90 lol," Bajarin wrote ⁴. His point is historical. Memory was a thin-margin trade for decades, and it now earns software margins on the strength of AI demand.

So the compute component, which sits at its baseline on this ledger, has its first confirmed evidence from the supply chain. Memory makers set how many accelerators can ship.

Micron's quarterly revenue, a year apart and the guide for next quarter

Compared

The data3 rows · sources

Unit: billion dollars

Item	Value	Source
Q4 fiscal 2025 reported	11.32	[1]
Q4 fiscal 2026 reported	54.23	[1]
Q1 fiscal 2027 Micron's guidance	61.5	[1]

Morningstar says the growth came from price

William Kerwin, a senior equity analyst at Morningstar, published his note on Oct. 1 and cut his fair value estimate for Micron to $700 from $850 ³. His first finding goes to the heart of the ledger's question. "Growth was led nearly entirely by pricing growth," Kerwin wrote ³. If that holds, the jump from $11.32 billion to $54.23 billion measures what buyers paid per bit, and only a small share of it measures new bits.

Kerwin then makes the cycle argument at full strength. "We maintain that the current paradigm is a tremendous cycle, but a cycle nonetheless," he wrote ³. He expects a peak in early 2028 and a steep fall after it. "We see memory supply doubling by 2028, driving a steep pricing decline across 2029 and 2031," Kerwin wrote ³. "After huge capital spending, we expect heady depreciation to commensurately drive margins back down to earth."

Micron's own chief financial officer hinted at the slowdown Kerwin describes. "We expect higher gross margins beyond fiscal (first quarter) for the remainder of fiscal 2027, with a more moderate rate of price increases," Mark Murphy said on the call ⁴. Shares slipped 0.6 percent in premarket trading on Oct. 1 ⁴.

Customer concentration adds a second limit. Micron's 10-K reports that over half of its fiscal 2025 revenue came from its top ten customers, with about half from the data center market ⁶. A few buyers with large AI budgets decide most of this demand. When those buyers slow, the contracts get renegotiated, since Micron's long-term agreements acknowledge that price and quantity are periodically negotiated ⁶.

Kerwin and Mehrotra agree on more than it first seems. Both say supply stays short through 2027. They split on what comes after, and on whether the money in hand reflects compute getting built or memory getting scarce.

What Micron's filing shows, and what rests on forecasts

The record

The data8 rows · sources

Column	Item	Source
In the SEC filing	$54.23 billion in fiscal fourth-quarter revenue	[1]
In the SEC filing	Cloud Memory unit at $16.28 billion	[1]
In the SEC filing	Quarterly capex of $10.77 billion	[1]
In the SEC filing	Top ten customers bought over half of fiscal 2025 revenue	[6]
Said on the call or forecast	Vast majority of 2027 HBM bit supply under agreement	[2]
Said on the call or forecast	Growth led nearly entirely by pricing, says Morningstar	[3]
Said on the call or forecast	Memory peak in early 2028, by Morningstar's forecast	[3]
Said on the call or forecast	Memory supply doubling by 2028, by Morningstar's forecast	[3]

Sanjay Mehrotra's contracts against William Kerwin's cycle

Both sides

The data2 rows · sources

Side	Who	Claim	Source
For	Sanjay Mehrotra	Micron has agreements for the vast majority of its 2027 HBM bits and sees supply tight through 2028.	[2]
Against	William Kerwin	Price drove nearly all the growth, and memory supply doubling by 2028 should bring a steep fall in prices.	[3]

Where this sits on the ledger

The method gives an SEC filing and delivered chips a confirmed step of 0.8 to 1.5 points. This piece moves compute up 0.6, under that floor, and says why. Revenue in dollars overstates the physical change. Kerwin's finding that price drove nearly all of the growth implies that bit shipments grew far slower than revenue, which jumped 379 percent, an inference the filing leaves open because Micron reports dollars. HBM is one input among many, and an accelerator still needs a fab, a package, a rack and a grid connection before it counts as energized compute.

What earns the step is the contract book. Most of 2027's HBM is spoken for, so accelerator makers plan to build at a rate that consumes it. Memory is also the binding limit, by Micron's own account. Both facts point the same way. Compute is being built as fast as memory allows, and memory sets that speed through 2028.

Micron's 8-K lifts the compute reading 0.6 points

The move

The data5 rows · sources

Measure	Value
Reading before this day	1.9
This piece's move	+0.6 (Compute, confirmed)
Band for confirmed evidence	0.8 to 1.5
Reading after the day (with 6 other pieces that day)	2.5
Distance to 100	97.5

By the numbers

• $54.23 billion in fiscal fourth-quarter revenue, against $11.32 billion a year earlier ¹
• Cloud Memory, the unit that sells HBM, took $16.28 billion in the quarter ¹⁶
• Gross margin reached 86.8 percent, up from 44.7 percent ¹
• About $61.5 billion is Micron's revenue guidance for its fiscal first quarter of 2027 ¹
• Capital spending ran $10.77 billion in the quarter and $27.37 billion across fiscal 2026 ¹
• Morningstar's fair value estimate fell to $700 from $850 ³
• Over half of fiscal 2025 revenue came from Micron's top ten customers ⁶

What to watch

Micron's next quarterly report will show whether revenue lands near $61.5 billion and whether HBM keeps outgrowing the company. A rise in bit shipments, stated in numbers, would confirm that more memory and more compute are moving, and would justify a larger step. Signs that would argue for reversing it: a cut to 2027 HBM contracts, a drop in quarter-on-quarter pricing faster than Murphy's "more moderate rate," or a capex pause. Kerwin's early-2028 peak is the date to hold against the record.