Micron and SanDisk both benefit from demand for memory and storage, but they are not interchangeable versions of the AI trade. Micron sells DRAM, including high-bandwidth memory, as well as NAND. SanDisk's business centers on NAND flash storage. Different products, fiscal calendars and cash-flow definitions need to remain visible before comparing the stocks.
This Sunday research uses October 16 completed regular-session closes and the latest reported financial quarters. Micron's fiscal Q4 ended September 3 and was reported September 30. SanDisk's fiscal Q4 ended July 3 and was reported August 5. They are not the same calendar quarter.
Compare the businesses before comparing the margins
Micron reported $54.229 billion of quarterly revenue, 86.80% GAAP gross margin and 80.70% GAAP operating margin. Its full-year product revenue—not its quarterly business-unit mix—was $100.679 billion of DRAM and $31.785 billion of NAND. Those represented 75.59% and 23.86% of fiscal-year sales. HBM is part of DRAM and must not be added again as a separate product-revenue category. Micron fiscal Q4 release, Micron 10-K.
SanDisk reported $8.965 billion of quarterly revenue and 84.60% GAAP gross margin. Its datacenter end market contributed $2.977 billion, or 33.21% of quarterly revenue. Datacenter sales are not a separately disclosed AI-only revenue segment, and SanDisk's end-market breakdown is not directly comparable with Micron's product breakdown. SanDisk fiscal Q4 release.
Both reported unusually strong memory-cycle economics. Extrapolating peak margins indefinitely would be a separate assumption. Product pricing, demand, customer commitments, supply additions and manufacturing execution can change the results; a higher current margin alone does not identify the better future stock return.
Customer funding reaches cash flow through different doors
Micron's fiscal Q4 operating cash flow was $43.973 billion. Its reported net capital expenditures of $10.774 billion reconcile from $11.110 billion of gross PP&E purchases, less $9 million of asset-sale proceeds and $327 million of government incentives. The company's adjusted free cash flow was therefore $33.199 billion.
Micron also reported $12.747 billion of customer contract-liability deposits in fiscal-year financing cash flows. That is an annual amount, not a quarterly OCF item. Subtracting it from Q4 operating cash flow would mix periods and remove an amount that was not in that OCF line in the first place.
SanDisk's quarterly operating cash flow was $7.126 billion. Less $43 million of net cash PP&E spending gives $7.083 billion of free cash flow. Its own adjusted measure then deducts $110 million for Flash Ventures and $1.938 billion for NBM prepaid deposits, producing $5.035 billion of adjusted free cash flow. Cash PP&E purchases alone do not capture all of the partnership and customer-funding economics. SanDisk 10-K.
These are clearly defined company measures, not a common standardized cash-flow league table. The useful question is what obligations and future deliveries accompany customer cash, and what investment the business still needs. The figures do not establish a repeatable annual yield at Friday's prices.
Friday's price damage was real, but the long averages were lower
MU closed $878.84, down 5.63% on Friday and 14.59% from the October 9 close. It was below its completed 20-day SMA of $1,033.00 and 50-day of $983.12, while above the 200-day at $717.84. The October 15 intraday low of $858.00 is a nearer lower reference; the surviving October 13 downward daily gap at $953.60-$978.50 is overhead.
SNDK closed $1,299.30, down 6.85% on Friday and 17.86% for the same completed week. Its 20-day SMA was $1,650.37, 50-day $1,593.05 and 200-day $1,210.71. The October 15 intraday low of $1,276.00 lies below the close; the remaining October 15 downward gap at $1,397.64-$1,402.02 is an overhead reference. SanDisk's separate listed history begins in 2025, so the chart does not pretend to have a standalone stock-price record since 2020.
For either chart, reclaiming an area and holding it on a daily closing basis would add evidence. A failed reclaim or a loss of the dated low would weaken the near-term picture. A gap is not a guaranteed target, and a daily retest is not completed by a momentary touch.
The next comparison should keep the same boundaries
Micron's September outlook for fiscal Q1 was $60.00-$63.00 billion of revenue. SanDisk's August outlook was $10.30-$10.80 billion for its own fiscal Q1; it is due for an update at its October 29 report, according to the company announcement. These are forward-looking ranges from different dates, not results already delivered.
The research verdict is to separate three questions: which memory exposure is desired, how customer commitments and investment shape durable cash, and what the price already assumes. This analysis supports neither a margin-based winner nor a valuation winner without a consistently defined earnings and cash denominator. Both charts show shorter-term weakness above their longer average; the next daily closes determine whether that changes.
See MU Daily Levels, SNDK Daily Levels and other comparisons.
This is market research only, not a recommendation to buy or sell.